Published on in Vol 9, No 10 (2022): October

Preprints (earlier versions) of this paper are available at https://preprints.jmir.org/preprint/37342, first published .
Guided Internet-Delivered Treatment for Depression: Scoping Review

Guided Internet-Delivered Treatment for Depression: Scoping Review

Guided Internet-Delivered Treatment for Depression: Scoping Review

Review

1Faculty of Health, Welfare and Organisation, Østfold University College, Halden, Norway

2Faculty of Health Sciences, Department of Behavioral Sciences, Oslo Metropolitan University, Oslo, Norway

3Department of Education, ICT, and Learning, Østfold University College, Halden, Norway

4Faculty of Computer Science, Albstadt-Sigmaringen University, Sigmaringen, Germany

5Division of Psychiatry, Haukeland University Hospital, Bergen, Norway

6Departement of Global Public Health and Primary Care, University of Bergen, Bergen, Norway

Corresponding Author:

Line Børtveit, MA

Faculty of Health, Welfare and Organisation

Østfold University College

Høgskolen i Østfold

Postboks 700

Halden, 1757

Norway

Phone: 47 93203985

Email: linebortveit@gmail.com


Background: Studies on guided internet-delivered treatment have demonstrated promising results for patients with depressive disorder.

Objective: The aim of this study was to provide an overview of this research area and identify potential gaps in the research.

Methods: In this scoping review, web-based databases were used to identify research papers published between 2010 and 2022 where guided internet-delivered treatment was administered to participants with depressive disorders, a standardized rating scale of depressive symptoms was used as the primary outcome measure, and the treatment was compared with a control condition.

Results: A total of 111 studies were included, and an overview of the studies was provided. Several gaps in the research were identified regarding the design of the studies, treatments delivered, participant representation, and treatment completion.

Conclusions: This review provides a comprehensive overview of the research area, and several research gaps were identified. The use of other designs and active control conditions is recommended. Future studies should provide access to treatment manuals, and more replications should be conducted. Researchers should aim to include underrepresented populations and provide reports of comorbidities. Definitions of adequate dosage, reports of completion rates, and reasons for treatment dropout are recommended for future studies.

JMIR Ment Health 2022;9(10):e37342

doi:10.2196/37342

Keywords



Depressive Disorder and Treatment Over the Internet

The number of people with access to the internet is considerable and increasing also in low-income countries [1]. As the number of people with access to the internet is sizable, internet-delivered treatment has the potential to reach more patients, be easily accessible, and be less time-consuming for the therapist per patient than more resource-intensive face-to-face therapies [2-4]. The COVID-19 pandemic has also demonstrated that situations might arise when face-to-face therapy can be less available, thus suggesting the benefits of internet-delivered treatments [5].

Depressive disorders, or clinical depression, are associated with great personal distress and high societal costs [6]. Common features of depressive disorders according to the Diagnostic and Statistical Manual of Mental Disorders [7] are sad, empty, or irritable mood and somatic and cognitive changes that decrease the ability to function at work and at home. As the number of people with clinical depression is increasing, there is a demand for effective and accessible treatments [8]. Meta-studies on internet-delivered psychological treatment show promising results for adults with mild or moderate depressive disorder [9-12], and this treatment option could be an accessible and less resource-intensive alternative to traditional face-to-face treatment [10].

Internet-delivered treatments typically involve working with different modules composed of reading assignments and tasks in a self-help format [13]. Treatments are often based on evidence-based treatment for depressive disorder; cognitive behavioral therapy (CBT); or other psychological treatments such as acceptance and commitment therapy, problem-solving therapy, positive psychology, or psychodynamic therapy [10,11,14]. These treatment options are accessible digitally through web-based programs such as web pages and phone apps and are available to the patient wherever there is internet access.

In therapist-guided internet-delivered treatment, additional guidance and support are provided by therapists, coaches, or other professionals over the internet via chats, emails, and telephone [14-16]. In unguided treatment programs, the patients usually have access to the treatment content, and some programs provide automated prewritten feedback. In guided treatment programs, a therapist often plays an active role in the treatment and guides the patient (or research participant) through the program. Studies have shown that both treatment formats could be effective and that a guided program is not necessarily superior to an unguided program [17,18] but that the inclusion of guidance could have an impact on treatment adherence [19].

A few recent meta-studies have focused primarily on guided treatments. Karyotaki et al [11] found guided internet-delivered treatments to have positive treatment effects, especially for patients with more severe depressive symptoms at baseline. Chan et al [12] found effectiveness in reducing depression and anxiety and lower attrition rates than previously reported for guided internet-delivered CBT. Carlbring et al [20] compared guided internet-delivered CBT with face-to-face therapy and concluded that the 2 treatments were equally effective for depression and several other psychiatric and somatic disorders.

To our knowledge, no recent review aimed at providing an overview and identifying potential research gaps focusing on guided treatments for patients with depressive disorder has been conducted.

Scoping Review

A scoping review is a method used to provide an overview of a research area. The PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) provides a framework with guidelines for conducting and reporting scoping reviews [21,22]. A key capacity of a scoping review is that it can synthesize research and describe what evidence is known and available in a confined area of research in the form of publicized empirical accounts. However, another important aspect of a scoping review is that it can inform and contribute to a research field by identifying potential gaps in knowledge.

In this scoping review, we focused on 4 overarching aspects of the included studies. We focused on (1) the design (and methods), (2) the treatments delivered, (3) the characteristics of the participants, and (4) how treatment completion was reported in the studies. We then considered potential gaps in the literature that should be taken into account in future research on internet-delivered treatment for depression.

Type of Design

In previously published reviews and meta-analyses on internet-delivered treatment for depression, randomized controlled trials (RCTs) have been the most prevalent methodological design [11,14-16]. Etzelmueller et al [10] reviewed guided internet-delivered CBT focusing only on nonrandomized pre-post designs to evaluate the intervention effectiveness in a clinical setting and found evidence of both acceptability and effectiveness. Effectiveness studies investigating potential effects of treatment programs in a real world clinical setting could provide stronger conclusions about expected treatment outcomes than efficacy studies conducted in a controlled environment with more “ideal settings.” In their systematic review of the implementation of internet-delivered treatments for depression in public health primary care settings, Rodriguez-Pulido et al [23] concluded that there were few studies outside the United Kingdom where this was investigated. Given the high prevalence of depression and the need for clinical evidence on the effectiveness of known treatment programs, it is of high relevance that a review of the available research and an evaluation of the study setting are warranted. Other factors regarding how studies are designed are also recommended for inclusion in a scoping review. These factors include descriptions of the comparator or control conditions (if used) in the intervention, the aims of the study, and the outcome measures used [24]. Including a variety of designs in a scoping review has the benefit of providing a more comprehensive overview of the research area [25]. At the same time, it is recommended to limit the inclusion of studies using designs related to answering the research questions (RQs) in the review [24]. In some research areas, the number of studies published can be quite extensive. Hence, some type of exclusion criterion is needed. This scoping review focused on efficacy or effectiveness studies that presuppose experimental and quasi-experimental designs, and therefore, studies with at least one control condition were included.

Type of Treatment

Reports on the properties of the treatment, duration, and other methodological choices are recommended for inclusion in scoping reviews [25]. These factors could provide a useful overview of the treatments delivered and contribute to the identification of potential research gaps. Internet-delivered treatments based on CBT have been the principal subject matter of several newer reviews [10,12,20,26,27] and have even been the most prevalent treatment approach in reviews where other treatment approaches were also considered [11,14,16]. For example, Karyotaki et al [11], who focused exclusively on guided internet-delivered treatment for depression, showed that most treatments tested were based on CBT (>70%) or problem-solving therapy. Tokgöz et al [16] and Garrido et al [14] reported similar findings as well.

When reviewing treatments, easy accessibility to treatment manuals is beneficial for transparency purposes and for making comparisons between studies feasible [28]. In addition, access to manuals is beneficial for future replication studies as well as for developing new treatments in which content from previously tested treatment programs is used. A review of trials in which psychological treatments were delivered for common mental disorders showed lower rates of access to the treatment manuals [28], and similar results were found in a review of internet-delivered CBT for adults in treatment for depression and anxiety [10]. There are, to our knowledge, no recently published reviews where the accessibility of treatment manuals in studies on guided internet-delivered treatment for depression is investigated.

Participant Characteristics

In highly tailored treatments with relevant content directed at patients with depression, detailed descriptions of the participants are important. Many recently published reviews and meta-analyses on internet-delivered treatment have focused on treatments directed at adults with depression [10,11,16,20], and several have focused on 1 particular population group (eg, perinatal women with anxiety and depression [15], young people with anxiety or depression or a combination of both [14], participants aged >50 years [29], or participants living in lower-income countries [30]). Given the focus on specific populations, these reviews provide limited insight into the area of guided internet-delivered treatment for depression as a whole. In this review, we wanted to provide an overview of sex, age, and location (country) representation in the studies to investigate whether some populations are over- or underrepresented.

Participants from Western countries have been overrepresented in previous reviews [10-12,14,15,20,26], with few or none of the included studies recruiting participants from countries outside the Western world. Martínez et al [30] reviewed studies with participants from lower-income countries and found only 6 studies.

There is a high prevalence of comorbid disorders to depression [31] as well as of comorbid anxiety disorder [32-34]. If the goal is to create effective treatments for the general population, it would also be advantageous to report whether the treatments were tested on participants with other diagnoses or additional comorbidities.

A synthesis including all studies regardless of the participant group in focus could contribute to the identification of potential research gaps in the represented populations.

Reports of Treatment Completion

Nonadherence and dropout rates have been reported to range from 0% to 75% in digital CBT treatments for depression [35], and the challenges of nonadherence have been discussed in several meta-studies [36-39]. Discontinuation of treatment hinders its effective delivery. First, patients not receiving an “adequate dose” of the therapy might not improve or may even experience a worsening of symptoms. Furthermore, limited resources (eg, therapy appointments) go to waste if patients discontinue treatment before an adequate dose is delivered, which could affect the ability of others to receive access to needed services and treatment [40,41]. With internet-delivered treatments, adherence has been defined as the extent to which individuals experience or engage with the content of the treatment [36,42]. Measures of adherence have included reports on the number of log-ins to the program, modules completed, time spent on the web, completion of different activities or use of web-based tools, posts made, pages viewed, replies to emails, forum visits, self-reports of completion of offline activities, and print requests made [43]. The adherence rate is commonly defined as the percentage of participants who complete treatment [39], which could include those participants who complete either the entire treatment or a specified amount of the lessons, modules, or exposure [44].

Completion of treatment as a measure of treatment adherence has been discussed as a problematic measure as treatment drop out might be the result of improvement [45], and “exposure” to a higher dosage of treatment does not necessarily mean better results [46]. In addition, participants might also use the technology in other ways than the developers intended [46], which can thus further skew the measured outcomes and interpretation of the results. The reasons or motivation for choosing the internet-delivered treatment could be of more importance for the results than the frequency or duration of exposure [46]. The adequate dose necessary to experience improvement could also vary among the different participants and user groups [45].

There is a lack of consensus on how to report treatment adherence [43,44]. Given that completion of treatment is described as a commonly used measure of adherence [39], this was also a focus of this scoping review. Reasons given (if reported) by participants for treatment discontinuation were also charted, which has often been described as not reported in many studies [39,44]. Understanding treatment discontinuation can provide useful information for treatment development and patient care and guide the design of future studies.

Aim and RQs

The aims of this scoping review were to analyze and describe currently available quantitative research on guided internet-delivered treatment for participants with depressive disorder, provide insight into this research area, and identify potential gaps in research.

We posed the following four RQs: (1) How are the studies designed? (RQ 1), (2) What types of treatments are delivered? (RQ 2), (3) What are the characteristics of the participants in the studies? (RQ 3), and (4) What is the treatment completion in the various studies? (RQ 4).


Scoping Review

The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines [21] for conducting systematic scoping reviews, described by Peters et al [24], were followed. Given that the aims of this scoping review were to describe the research and identify the potential research gaps, no quality assessment of the included studies was conducted.

Eligibility Criteria

Quantitative studies published in peer-reviewed journals between January 1, 2010, and June 4, 2022, were eligible for inclusion. Full-text accessible publications in the English or Scandinavian languages were included.

Even though this scoping review could have included noncontrolled studies, we restricted the inclusion criteria to controlled experimental studies where at least one condition stipulated that participants received guided internet-delivered treatment to reduce the potential extensiveness of this review. Reviews, meta-analyses, conceptual articles, and nonempirical articles were excluded.

A standardized rating scale for depressive symptoms (eg, Center for Epidemiological Studies-Depression [48], Patient Health Questionnaire-9 [49], and Montgomery-Åsberg Depression Rating Scale [50]) had to be used as the primary outcome measure throughout the study. To secure a comparable group of participants and limit the focus of the review, only studies in which the participants initially scored mild or moderate for depression were eligible for inclusion. Studies focused on preventing depressive disorder or promoting psychological well-being were excluded. Studies including participants with comorbid disorders were accepted as long as depressive symptoms were a primary outcome measure. We implemented no limitations regarding participant age, which typically has been the case in previous reviews [10,11,16,20,51]. We included studies with treatments directed at children as well as teenagers and young adults, thus allowing for comparisons between age groups, providing insight into age representation in the studies, and identifying potential studies that were previously excluded. We also assumed that younger people were more adept at using digital solutions, and therefore, there would be a vast number of studies with treatments directed at this subpopulation.

For this scoping review, treatments had to be delivered over the internet and accessible wherever the participants had access to the internet (the device used by the participants was not decisive, and both phone apps and web page–available interventions were included). Studies in which the participants were required to be in a specific location to have access to the treatment (eg, at home, in school, or at the psychologist’s office) were excluded. The guided internet treatments had to be a stand-alone treatment and not a supplement to face-to-face treatments. Only treatments in which the participants received guidance from a trained guide during the treatment were eligible. To be trained was defined as having a degree in psychology, social work, or nursing or other relevant education or being a student, in training, or a layperson and receiving special courses or training in the methods and supervision from a trained professional. The guidance had to be implemented during the entire treatment and not limited to measures and testing or reminders to complete web-based tasks.

See Multimedia Appendix 1 for the coding manual used.

Information Sources

The second author (AD) conducted a systematic search on June 4, 2022. The scientific databases PubMed, Scopus, PsycINFO, MEDLINE, and ERIC were searched. See Multimedia Appendix 2 for details about the search.

A total of 28 published systematic reviews on internet-delivered treatment (Multimedia Appendix 3 [10,11,14-16,20,27,29,30,51-69]) were hand searched by LB for relevant studies not identified in the literature search. The identified studies were screened using the same criteria applied when screening the database records.

Selection of Sources of Evidence

After removal of duplicates using the EndNote (version 20; Clarivate Analytics) duplicate finder followed by manual removal, the results were imported into the systematic review research tool Rayyan (Rayyan Systems Inc) [70] and screened by the first author (LB) for inclusion. Screening was performed by first reading the title and abstract and thereafter by screening the full-text articles. For studies where the eligibility was unclear, the fifth author (ANH) was consulted, and an agreement was reached after discussion between the 2 authors.

Data Items

Overview

The data were extracted and charted by LB. Author names, title of the article, journal, and year of publication were extracted as well as the items described in the following sections related to the 4 RQs. A detailed description of the extraction and charting of the data is provided in Multimedia Appendix 4 [7,71,72].

RQ 1: How Are the Studies Designed?

To answer this question, information about research design, control conditions, whether the studies were considered to be efficacy or effectiveness studies, and the outcome measures collected in the studies was charted.

RQ 2: What Types of Treatments Are Delivered?

To answer this question, information about the treatments, including treatment approaches, accessibility of treatment manuals, names of the treatments, by whom the guidance was delivered, and the duration of the treatment, was charted.

RQ 3: What Are the Characteristics of the Participants in the Studies?

To answer this question, information about the participants was charted. This included the number of participants, sex, mean age, age group in focus, reports of comorbid disorders, and the countries from which the participants were recruited.

RQ 4: What Is the Treatment Completion in the Various Studies?

To answer this question, information about treatment completion was charted, including if a definition of treatment completion was provided, the number of participants defined as completers, and reasons for discontinuation of treatment (if provided).


Selection of Sources of Evidence

The results of the screening process are presented in Figure 1. The literature search resulted in 4324 records, of which 98 (2.27%) were included in this scoping review.

The hand search of 28 published reviews yielded 13 additional studies. Thus, the total number of studies included in this review was 111.

Figure 1. Results from the screening process and literature search. Flow diagram showing inclusion and exclusion strategy.
View this figure

Synthesis of Results

In Multimedia Appendix 5 [17,73-182], the data charted from and the characteristics of the different sources of evidence are presented. Multimedia Appendix 5 provides an overview of the 111 included studies.

Study Design and Methods

The first RQ—“How are the studies designed?”—was related to what types of study designs and methods that were applied in the studies.

Study Design

Most publications (110/111, 99.1%) were RCTs. A total of 0.9% (1/111) were prospective cohort studies.

Control Condition

A total of 52.3% (58/111) of the studies included at least one active control condition (eg, access to other treatments or variations of the treatment). Of the 58 studies considered, 38 (66%) solely had active controls, whereas the other 20 (34%) used a combination of active and inactive controls. In addition, 47.7% (53/111) of the included studies had exclusively inactive control conditions (eg, no treatment, waitlist, attention control, or treatment as usual).

Efficacy and Effectiveness

A total of 81.1% (90/111) of the studies were defined as effectiveness (43/111, 38.7%) or efficacy studies (47/111, 42.3%). The remaining 18.9% (21/111) did not provide a definition.

Outcome Measure

A total of 14 different psychometric scales were used to measure depressive symptoms in the studies. In 17.1% (19/111) of the studies, a combination of different measurement scales was used as a primary outcome measure. In Multimedia Appendix 5, all relevant measurement scales used in the studies are charted. The 3 most applied outcome measurement scales for depressive symptoms were the Patient Health Questionnaire-9 [49], Beck’s Depression Inventory [183], and the Center for Epidemiological Studies-Depression scale [48].

Research Gaps in Study Design and Methods

Table 1 provides an overview of the identified research gaps with regard to how the studies were designed.

Table 1. Identified gaps in the reviewed literature regarding design.
Identified gapReasonReportPercentage of studies reporting
Lack of diversity in research designFew studies with designs other than RCTaOnly 1 study with other design (<1%)100% of the studies reported the design used
Need for more studies with an active control conditionRelatively many studies with an inactive control condition47.7% of the studies had only an inactive control condition100% of the studies described the control condition
Large variations in the outcome measure usedSeveral different measurement scales and combinations of these were used14 different measurement scales were used; 19 studies where combinations of different measurement scales were used100% of the studies reported the outcome measure used

aRCT: randomized controlled trial.

Treatment Characteristics

The second RQ—“What types of treatments are delivered?”—focused on what types of treatments were delivered and how the treatments were designed.

Treatment Approaches

Table 2 provides an overview of all the approaches used. A total of 123 treatments were tested. In 6.3% (7/111) of the studies, treatments were based on a combination of different approaches (eg, behavioral activation and physical activity [73] or problem-solving therapy and cognitive therapy [74]). A total of 1.8% (2/111) of the studies included several experimental arms that received treatments based on different approaches. In Kladnitski et al [75], one group received CBT, one group received CBT in combination with mindfulness, and one group received mindfulness exclusively. In the study by Stiles-Shields et al [76], one group received behavioral activation, and one group received CBT. For an overview of the treatment approaches used in the different studies, please see Multimedia Appendix 5.

Table 2. Treatments tested as stand-alone approaches, in combination, or as one of several arms in the studies (n=123).
Treatment approachesTests, n (%)
Acceptance and commitment therapy4 (3.3)
Behavioral activation9 (7.3)
Cognitive behavioral therapy82 (66.7)
Information1 (0.8)
IPDTa: affect-focused psychodynamic psychotherapy2 (1.6)
Life review therapy1 (0.8)
Mindfulness4 (3.3)
Physical activity3 (2.4)
Problem-solving therapy13 (10.6)
Psychodynamic treatment1 (0.8)
Sleep diary1 (0.8)
Social cognitive theory1 (0.8)
Stress process model1 (0.8)

aIPDT: internet-based psychodynamic therapy.

Treatment Manual

None of the studies provided easy access to the entire treatment manual. Many studies included brief descriptions of the treatment, such as a table describing the treatment content. Several studies referred to previous publications for a more detailed description of the treatment, but even in those cases, the manuals were not accessible. In all, 2.7% (3/111) of the studies provided more extensive treatment descriptions in the study protocol [77] or in the supplementary material or appendix [78,79].

Name of Treatment

In all, 71.2% (79/111) of the studies referenced a named treatment program. The most frequently identified treatment programs were different versions of The Wellbeing Course (8/111, 7.2%) [80] and The Sadness Program (7/111, 6.3%; including culturally adapted versions) [184].

Guidance

Only 0.9% (1/111) of the studies [81] did not report the background or training of the guides. Trained professionals delivered the guidance in 67.6% (75/111) of the studies. Most of the guidance was delivered by psychologists, social workers, and nurses, but there were also studies where guidance support was delivered by lay counselors [82] and nonprofessional volunteering telephone counselors [83] who did receive some training beforehand. A total of 6.3% (7/111) of the studies had research staff and authors providing the guidance, and 25.2% (28/111) of the studies had students or professionals in training supporting the participants.

Duration

Most studies (101/111, 91%) described the duration of the treatment in weeks, months, or years, and often the participants had to complete 1 module or session per week. A total of 3.6% (4/111) of the studies described the number of sessions or modules that should be completed without reference to time [84-87]. In total, 5.4% (6/111) of the studies did not describe the duration of the treatment [88-93]. The longest treatment lasted for 52 weeks [78], and the shortest lasted for 3 weeks [94]. For the 91% (101/111) of the studies where it was possible to chart duration in weeks, the mean treatment duration was 9.3 (SD 5.6) weeks with the range being 3 to 52 weeks, and the median was 8 weeks.

Research Gaps Regarding the Treatments Delivered

In total, 2 research gaps regarding types of treatments delivered were identified in the included studies. First, none of the studies provided easy access to a treatment manual.

Second, there was large variation in the treatment programs used. Only 47.7% (53/111) of the studies tested treatments that were used in at least one other study included in this review. This points to a lack of replications. However, only 71.2% (79/111) of the included studies reported the name of the treatment program, and unidentified replication studies are possible.

Participant Characteristics

The third RQ—“What are the characteristics of the participants in the studies?”—was related to the participants in the included studies.

Number of Participants

There were a total of 11,851 participants across all studies. Not all participants from all studies were included as some study arms did not fulfill the inclusion criteria (eg, studies where a comparison group did not receive web-based treatment or had a diagnosis other than depression). The mean number of participants with relevant conditions was 106.8 (SD 151.83, median 52, range 9-949).

Sex of Participants

Table 3 summarizes the representation of sex in the studies. The studies had an average of 74% female participants (median 76.6%, range 12.4%-100%). In 7.2% (8/111) of the studies, sex was not reported [76,95,96] or was reported for the total sample but not separated for the different conditions [97-101]. In total, 8.1% (9/111) of the studies included only women and had treatments directed at maternal depression [84,87,88,102-105], patients with breast cancer [106], or female adolescents [107].

A total of 7.2% (8/111) of the studies included <50% women. Of these 8 studies, 6 (75%) had participants with comorbid disorders (heart problems [108-111], HIV [112], and kidney diseases [113]), 1 (12%) was directed at a Kurdish population in Sweden [114], and 1 (12%) was directed specifically at army Veterans [115].

Table 3. Female participants (N=111).
Percentage of female participantsPublications, n (%)
0% to 20%2 (1.8)
21% to 40%4 (3.6)
41% to 60%7 (6.3)
61% to 80%60 (54.1)
81% to 100%35 (31.5)
NRa3 (2.7)

aNR: not reported.

Age of Participants

A total of 5.4% (6/111) of the studies did not report the participants’ ages [76,85,88,101,104,116]. The mean age across the remaining 94.6% (105/111) of the studies was 40.9 (SD 11.6, median 42.3, range 15.8-69.6) years.

Age Group in Focus

None of the included studies had treatments directed at children. A total of 9.9% (11/111) of the studies included teenagers or young adults. Most studies (96/111, 86.5%) had treatments directed at adults. A total of 3.6% (4/111) of the studies included solely older adults [117-120].

Comorbid Disorders

In 24.3% (27/111) of the studies, comorbidities or secondary diagnoses besides depressive disorder were not reported. In 26% (7/27) of these studies, comorbidities were stated as being included, but no description of these comorbidities was provided. Most studies (68/111, 61.3%) included participants with other Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), Axis I disorders [7] (eg, anxiety disorders, posttraumatic stress disorder, and eating disorders) in combination with depression.

In all, 19.8% (22/111) of the studies included participants diagnosed with both depression and a physical disease (eg, renal diseases [78,113], breast cancer [106], and multiple sclerosis [121]). In 5.4% (6/111) of the studies, participants were diagnosed with a combination of physical diseases and mental disorders or other DSM-IV Axis I disorders in addition to depression (eg, cancer, anxiety and stress [95,122], or diabetes and anxiety [123].

Countries of Recruitment

See Table 4 for an overview of all the countries in which the participants were recruited. Most studies (104/111, 93.7%) were conducted in and included participants from Western countries, but non-Western countries such as Iran [107], Colombia [126], and Indonesia [82] were also represented. In total, 2.7% (3/111) of the studies included a population that was considered to have a culturally different background than most participants recruited. These culturally different populations were Turkish migrants in the Netherlands [124], the Kurdish population in Sweden [114], and Chinese Australians [127].

Table 4. Countries where participants were recruited (N=111).
CountriesPublications, n (%)
Australia20 (18)
Brazil and Peru1 (0.9)
Canada6 (5.4)
China1 (0.9)
Colombia1 (0.9)
Finland2 (1.8)
Germany7 (6.3)
Indonesia1 (0.9)
Iran1 (0.9)
Ireland1 (0.9)
Netherlands15 (13.5)
Norway1 (0.9)
Romania1 (0.9)
Spain2 (1.8)
South Korea1 (0.9)
Sweden26 (23.4)
Switzerland2 (1.8)
Switzerland and Germany1 (0.9)
United Kingdom6 (5.4)
United States15 (13.5)
Research Gaps Regarding the Participants in the Studies

In Table 5, research gaps with regard to the participants in the studies are identified.

Table 5. Identified gaps in the reviewed literature regarding characteristics of the participants.
Identified gapReasonReportPercentage of studies reporting
Female participants overrepresentedMore female than male participants in the studiesThe studies had an average of 74.1% female participantsSex was reported in 97.3% of the studies
Lack of studies directed at teenagers and young adultsFew studies of treatments directed at teenagers or young adults11 studies directed at teenagers or young adults100% of the studies reported or provided sufficient information to draw conclusions about age group in focus
Lack of studies directed at older adultsFew studies of treatments directed at older adults4 studies included solely older adults100% of the studies reported or provided sufficient information to draw conclusions about age group in focus
Lack of reports of comorbid disordersSeveral studies where comorbid disorders were not described in detail or reported24.3% of the studies did not include reports of comorbid disorders75.7% of the studies reported comorbidity
Non-Western participants underrepresentedFew studies with participants from non-Western countries6.3% of the studies recruited participants from non-Western countries100% of the studies reported or provided sufficient information for conclusions about origin
Treatment Completion

The fourth RQ—“What is the treatment completion in the various studies?”—was related to treatment completion in the studies, including if the researchers provided a definition of adequate dosage for the treatment to be considered completed, the number of participants completing the treatment, and reasons provided for treatment dropout.

Definitions of Treatment Completion

Of the 111 studies, 22 (19.8%) provided a clearly stated definition of treatment completion.

Completion was often defined as completing all modules or sessions [77,87,128] or a majority of the modules (eg, 5 of 8 modules [82]). A total of 0.9% (1/111) of the studies defined completion as having started in the last module [129].

Number of Completers

Overall, 80.2% (89/111) of the studies provided information about the number of participants who completed all the treatment modules or lessons or fulfilled a stated definition of treatment completion. See Table 6 for an overview of the percentage treatment completers in the 80.2% (89/111) of studies. In 34% (30/89) of these studies, <50% of the participants completed the treatment. In 66% (59/89) of these studies, >51% of the participants completed the treatment; of these 59 studies, there were 5 (8%) with >90% of the participants completing the treatment [118,130-133].

Table 6. Treatment completers (N=89).
Percentage of treatment completersPublications, n (%)
0% to 20%10 (11)
21% to 40%14 (16)
41% to 60%21 (24)
61% to 80%26 (29)
81% to 100%18 (20)
Reasons for Noncompletion

A total of 15.3% (17/111) of the studies clearly stated reasons why participants did not complete the treatment. In 100% (17/17) of these studies, several reasons for noncompletion were reported. The most reported reason was that some of the patients lacked time to complete the treatment, as reported in 71% (12/17) of these studies. Treatment not meeting personal needs (10/111, 9%) and personal problems or sickness (10/111, 9%) were also described by patients as reasons for not completing. In 8.1% (9/111) of the studies, some of the participants dropped out without providing reasons for noncompletion. See Table 7 for details from the 15.3% (17/111) of the studies.

In the remaining studies (94/111, 84.7%), reasons for noncompletion were either not stated (88/94, 94%) or not clearly stated (6/94, 6%). During coding, we noted that several studies provided reasons for attrition (dropout from the study; eg, failure to complete follow-up questionnaires), but these data were not charted in this review.

Table 7. Reasons participants provided for noncompletion of the treatment in the 17 studies where this information was described.
ReasonStudy

Boele et al [139], 2018Boeschoten et al [121], 2017Geraedts et al [74], 2014Heller et al [87], 2020Høifødt et al [138], 2013Karyotaki et al [144], 2022Kenter et al [137], 2016Kleiboer et al [136], 2015Lappalainen et al [132], 2015Nadort et al [113], 2022O’mahen et al [88], 2014Pots et al [145], 2016Preschl et al [134], 2011Ström et al [81], 2013Van der Zweerde et al [98], 2019Wagner et al [135], 2014Westerhof et al [79], 2019
No reason provideda







Not meeting personal needs






Recovery








Preferred other treatment or part of the treatment










Technical difficulties










Lack of time




Motivation







Personal problems or sickness






a✓: indicates that at least one participant in the study stated the reason as a cause for treatment noncompletion.

Research Gaps Regarding Completion of Treatment

In Table 8, research gaps regarding the definition of treatment completion, the rate of completion, and the reasons provided for treatment dropout are presented.

Table 8. Identified gaps in the reviewed literature regarding treatment completion.
Identified gapReasonReportPercentage of studies reporting
Lack of clear definitions of treatment completionFew studies where completion was definedA minority (n=22) of the studies provided a clearly stated definition of adequate or necessary dosage of the treatment for it to be considered completed19.8% of the studies provided definitions of treatment completion or adequate dosage
Lack of reports of treatment completionSeveral studies without reports of the number of participants who completed the treatment89 studies provided information about the number of completers (completed all the treatment modules or fulfilled a stated definition)80.2% of the studies reported the number of participants who completed the treatment
Lack of reports on reasons for treatment dropoutMost studies did not provide reasons for participants dropping out of treatment17 studies clearly stated reasons for noncompletion of the treatment15.3% of the studies reported reasons for discontinuation of treatment

Summary of Evidence

In this scoping review, we identified 111 studies published between 2010 and 2022 on guided internet-delivered treatment for participants diagnosed with depression.

Study Design and Methods

There was a high degree of uniformity regarding research designs, with 99.1% (110/111) of the studies using RCTs; these results are similar to results from previously published reviews on internet-delivered treatment for depression [11,14-16]. We anticipated to identify controlled experimental studies without randomization (eg, comparing the effects for men vs women), including studies with multiple single-case designs with within-person control or other variations of research designs. Even though we did not exclude nonrandomized studies, our findings might still be a result of the quite strict inclusion criteria, such as the studies needing to include at least one control condition. A scoping review including noncontrolled studies might produce results in which further information about the treatments is identified [47] and could be useful for updating treatments in an applied setting [10].

There were an equal number of efficacy and effectiveness studies in the part of our sample where this was reported. Given that one of the inclusion criteria stipulated that participants should have depressive disorder, one might expect the identification of a higher number of effectiveness studies conducted with patients in clinical settings. However, the criteria that the studies had to have at least one control condition may have indirectly led to the exclusion of these types of studies. In a clinical setting, it might have been viewed as impractical or even unethical to not offer the same conditions to all patients. This might also explain why a large amount of the studies had an active control condition or a combination of active and inactive control conditions.

Even though most studies (58/111, 52.3%) had at least one active control condition, 47.7% (53/111) had an inactive control condition. As active control is preferable [185], this represents a gap in the research, and future studies should aim to be designed with an active control condition.

There was quite a large variation regarding outcome measures considering that only standardized measurement scales were accepted. Many studies used combinations of various scales. A possible reason might be that studies were conducted by a variety of research teams in different countries and that personal preferences and traditions could influence such decisions. The use of different outcome measures might not be problematic, and treatment effects could still be compared, but it could represent a possible scaling issue if there are large variations in how depression is defined. There is a risk that different phenomena were measured in the different studies, where some behaviors defined as depressive symptoms in one study might not be considered so in another study. In addition, what is used as primary outcome measures varies and in many instances, is not specifically mentioned or defined as the primary outcome in the trial.

Treatment Characteristics

We identified several different treatment approaches, but most studies (81/111, 73%) used some variation of CBT. This might represent the standard treatments recommended for patients with depression [186] and is also similar to the findings of a previous review on guided internet-delivered treatment for depression [11]. This could be an indicator that the treatments were implemented based on evidence-based studies and results.

With no publications where the treatment manual was easily accessible, the results are weaker than in previous reviews [10,28], and this gap in research should be addressed in future studies. The lack of accessibility to treatment manuals makes the studies less transparent as well as making comparisons and replications more difficult.

A large variety of treatment programs was used, which could indicate that more studies using the same programs would be beneficial as opposed to every research team investigating a new program. However, lack of accessible treatment manuals and with several unnamed treatments used in the included studies, it is possible that some studies used the same treatment programs without it being identified in this review.

Trained professionals accounted for most of the guidance, which was expected for studies with participants diagnosed with clinical depression, and these findings were in line with previously published reviews [10,11]. However, research staff and students were also used as guides in several studies (35/111, 31.5%).

In line with the common duration of face-to-face sessions in CBT for depression [187,188], most treatments in our sample lasted between 5 and 12 weeks.

Participant Characteristics

There were large variations in the number of participants included in the studies. This scoping review evaluated studies with a combined total of >11,000 participants and thus provided a large demographic profile of the participants studied.

Female participants were overrepresented in the studies, with an average of 74%. Although this might indicate a sex prevalence of depression, treatments should be tested for all potential target populations. Those studies directed at participants diagnosed with both depression and a comorbidity or physical disease (eg, heart failure [108]) had more male participants. Our review also identified 8.1% (9/111) of the studies directed at women only, mostly with the aim of reducing maternal depression. Studies on treatments directed at maternal depression have often been excluded from previous reviews [52] or reviewed separately [15].

Participants from non-Western countries were also underrepresented in the studies. Given the increasing access to internet-connected devices and the steady rise in the number of people in need of treatment in these countries [189], more studies with non-Western participants would be advantageous.

Studies with treatments specifically directed at teenagers or young adults and older adults were underrepresented in the research. However, there was some overlap in some of the included studies in which several studies recruited and enrolled participants aged <30 years and >60 years. The prevalence of depressive disorders is higher in young adults than in any other age group in high-income countries [189], and providing and testing treatments for this targeted group should be prioritized.

We identified several studies with computerized treatments directed at children. However, treatments directed at children often involved working together with a therapist or coach at school or in a therapist’s office, and these studies were excluded from our review because of the limited accessibility and requirement to be in a specific location. A future review aiming to include treatments for this age group could focus on computerized program treatments rather than internet-delivered treatments.

This review revealed deficient reporting of comorbid conditions experienced by the participants, which is problematic because of the high prevalence in the patient group [31]. It is reasonable to assume that there were participants with comorbidities or secondary diagnoses in most of the studies as long as these comorbid conditions were not used as an exclusion criterion. Reports on this should be included in future studies. In the studies where this was reported (84/111, 75.7%), DSM-IV Axis I disorders, especially anxiety disorders, were the most prevalent. Given the high prevalence of comorbid anxiety with depressive disorder [32-34], this was as expected. A total of 0.9% (1/111) of the studies [134] excluded participants with symptoms of anxiety disorders or posttraumatic stress disorder, which could limit the ability to generalize the findings. Testing treatments directed at patients without other comorbid DSM-IV Axis I disorders could, by contrast, lead to highly targeted treatments. Specialized and individualized treatment programs could potentially reduce the problem of treatment dropout, that is, assuming that the participant continues to deem all modules or lessons as highly relevant for treatment success. Further research on how comorbid conditions affect the response to treatment and how treatment programs should be amended is needed.

This scoping review led to the identification of several studies (22/111, 19.8%) in which participants had physical diseases or disorders. For patients with chronic pain, diabetes, cancer, or renal disease or kidney failure, the flexibility and accessibility of the internet-delivered format could be crucial for implementation of the treatment.

Treatment Completion

A minority of the studies (22/111, 19.8%) provided a clearly stated definition of what was considered an adequate dosage of the treatment for it to be considered completed. It is problematic if treatment programs are not evaluated with the aim of ensuring access to effective treatment components. If it is expected that participants will not interact with all the modules or lessons in the program, it could be argued that the treatments should be made shorter and only include the most effective components. It is also problematic if most studies make conclusions regarding treatment efficacy or effectiveness based on a study sample where dosage or interaction with treatment were not evaluated.

Most studies provided information about the number of participants who completed all modules or lessons in the program. As a result, we synthesized this information although these data could be a somewhat problematic measure of treatment adherence [45,46]. Several studies included optional modules that were directed at specific problems (eg, insomnia) that might not have been applicable to all participants. Treatment adherence is considered a challenge for both psychotherapy in general [41] and digital psychotherapeutic treatments [36-39]. Thus, it would be advantageous to have some consensus when reporting nonadherence to treatment to be able to effectively target the challenging areas of nonadherence. To compare across studies, an operationalization of treatment completion and reporting of the number of participants considered completers are needed in future studies.

A minority of the studies (17/111, 15.3%) provided reasons for noncompletion of the treatment; this is in line with previous findings [39,44]. The most reported reasons were primarily associated with the participants’ personal experiences and everyday challenges. These reasons might be expected from all participants. Other reasons such as reports of technical difficulties and the treatment not meeting personal needs and preferences were provided as rationales for nonadherence to treatment programs. This information could be of high value when developing and refining digital treatments. Dropout rates because of aspects of the treatment should be addressed, and the collection of data from participants who drop out is a necessary future step in this line of research.

In 47% (8/17) of these studies, treatment dropout as a consequence of recovery was reported [87,88,134-139]. It would be highly interesting to assess whether dropout as a result of recovery was also reported in 100% (111/111) of the studies. This lack of reporting is a problem that is discussed in other reviews [44]. If a large number of participants drop out because of recovery early in treatment, it could indicate that some of the components were highly effective or that the participants were misdiagnosed. Furthermore, dropout because of recovery could also indicate that it would be advantageous to deliver the treatment program in a stepped care model where treatment and data collection are conducted with the expectation that participants will recover during the treatment and therefore, should be considered treatment completers. A stepped care model would also make it possible to reduce the resources spent on each patient, and guidance by a therapist could be delivered only to participants who do not recover when the treatment is delivered unguided.

Limitations

The first author screened the results from the literature search and extracted and charted the data without reliability measures being conducted. The fifth author (ANH) was consulted when the eligibility of a study was unclear, but the studies discussed were selected by the first author. This is a limitation of this scoping review. It is possible that screening, extraction, and charting would have led to different results if conducted by several researchers.

In an effort to make the treatments included in the scoping review comparable, only guided treatments were included. However, it is important to acknowledge that there is variation in the guidance offered in the different studies. In addition to differences in who delivered the guidance, the frequency, modality, and content of the guidance also varied across the studies. In some studies, guidance was available exclusively upon request (eg, the study by Beiwinkel et al [140]) and, in other studies, guidance was initially delivered to all participants and thereafter available only upon request (eg, the studies by Kladnitski et al [75] and Smith et al [141]). Other studies included weekly feedback with brief emails (eg, the study by Ünlü Ince et al [124]), 5- to 10-minute therapist contact (eg, the study by Mullin et al [142]), or phone calls or instant messaging (eg, the study by Dear et al [143]). The large variation in guidance and the therapist’s role in the treatment make the methods used in the different studies less comparable. It is possible that participants in studies with guidance solely upon request completed the entire treatment unguided.

The comprehensiveness of the study was also reduced owing to our restrictions on the year of publication. However, previous years have been thoroughly covered in other reviews. Despite this limitation, we attempted to provide an extensive and large sample of studies in our review. There are also a limited number of studies on internet-delivered treatments in the initial years of the internet, which could also be related to participants’ limited availability and access to the internet in general.

Other limitations of our findings are the exclusion of studies published in languages other than English or one of the Scandinavian languages and the exclusion of gray literature or literature pieces that were not formally published. By excluding gray literature, there is a chance of publication bias in that studies considered to have novel or significant results will have a greater chance of being published [190].

Future Review Studies

A scoping review where inclusion is not limited to controlled studies could potentially provide a comprehensive overview of the research area. Studies investigating how a treatment works could lead to a lot of additional and important information [47]. Therefore, inclusion of these types of studies in future reviews would be beneficial.

Given our restriction to only include stand-alone internet-delivered treatments in this scoping review, several studies were consequently excluded. Therapies in which internet-delivered treatment is provided in combination with other treatments could lead to efficient and effective outcomes for participants with reduced costs and use of resources. This cost-effectiveness of treatment and reduction in use of resources could allow for an increase in participants’ access to needed services and treatment therapies. For example, patients with more severe symptoms of depression could have greater access to needed therapy in combination with the already existing treatment practices. In future reviews, the inclusion of studies in which the internet-delivered treatment is used as a supplement to other treatments would be beneficial to assess. Comparisons between stand-alone and supplemental treatments could also be an area of interest.

A potential interesting item to investigate could be how the treatments were made available to the participants. As we included all studies independent of how the treatment was accessed by the participants (as long as it was delivered over the internet), all formats were included in this review but not described in detail. We believe that treatment delivery via web-based programs, websites, or apps might not represent vastly different user experiences (eg, the difference between opening an app on a smartphone and visiting a website on the same device could be minimal). At the same time, usability, design, user interface, and functionality of the treatment program could be of great importance, and this could be an interesting topic to investigate for a future study.

Studies examining the preventive effect of internet-delivered treatment for depressive symptoms would also make a highly relevant and interesting area for a future review. If cases of depression could be prevented using low-cost and highly accessible methods of treatment delivered over the internet, this would be both ethically and economically beneficial, and research on this area should be prioritized.

Conclusions

A total of 111 studies on guided internet-delivered treatment were suitable for inclusion in this scoping review. The RCT design was the most prevalent, and the use of other designs and active control conditions is recommended for future studies. Variations in the outcome measurement scales applied were identified, and more consistency could be beneficial. Lack of accessibility to treatment manuals and few replications where the same treatment program was tested were also discovered and discussed. In future research, underrepresented populations (men, teenagers or young adults, older adults, and non-Western populations) should be included to a greater extent. Given the high prevalence of comorbidities in participants with depressive disorder, the reports of comorbidities in the included studies were somewhat deficient, and future research should investigate this further. Few studies provided definitions of when the treatments were considered completed (22/111, 19.8%) and reasons for treatment dropout (17/111, 15.3%). Most studies (89/111, 80.2%) provided information about the number of participants who completed all treatment modules or lessons or fulfilled a stated definition of treatment completion. There were more studies identified in which >51% of the participants completed the treatment compared with studies in which <50% of the participants completed the treatment. Finally, in only 4.5% (5/111) of the studies, >90% of the participants completed the treatment.

Acknowledgments

The authors thank Leanne Noelle Strom Torgersen for proofreading and helping with the preparation of the manuscript. TN was funded by ForHealth (309264).

Data Availability

The original contributions presented in this study are included in the paper and appendixes. Further inquiries can be directed to the corresponding author.

Authors' Contributions

LB, AD, ANH, TN, and SS collectively contributed to the conception and design of the study. LB reviewed the literature. AD designed the strategy and conducted the search. Screening and data extraction were conducted by LB in consultation with ANH. Analysis and manuscript drafting were carried out by LB with support from ANH, TN, AD, and SS. All authors participated in the interpretation of the results and reviewed, edited, and approved the final version of the manuscript.

Conflicts of Interest

None declared.

Multimedia Appendix 1

Coding manual.

DOCX File , 21 KB

Multimedia Appendix 2

Search terms and Boolean operators.

DOCX File , 20 KB

Multimedia Appendix 3

Screened reviews.

DOCX File , 25 KB

Multimedia Appendix 4

Data items extracted and charted from the included studies.

DOCX File , 25 KB

Multimedia Appendix 5

All the included studies.

XLSX File (Microsoft Excel File), 60 KB

  1. Individuals using the internet (% of population). The World Bank.   URL: https://data.worldbank.org/indicator/IT.NET.USER.ZS [accessed 2020-12-18]
  2. Kazdin AE. Addressing the treatment gap: a key challenge for extending evidence-based psychosocial interventions. Behav Res Ther 2017 Jan;88:7-18. [CrossRef] [Medline]
  3. Kazdin AE, Blase SL. Rebooting psychotherapy research and practice to reduce the burden of mental illness. Perspect Psychol Sci 2011 Jan 03;6(1):21-37 [FREE Full text] [CrossRef] [Medline]
  4. Nordgreen T, Repål A. Veiledet internettbehandling: digitale verktøy for psykisk helsehjelp. Oslo: Gyldendal; 2019.
  5. Wind TR, Rijkeboer M, Andersson G, Riper H. The COVID-19 pandemic: the 'black swan' for mental health care and a turning point for e-health. Internet Interv 2020 Apr;20:100317 [FREE Full text] [CrossRef] [Medline]
  6. Kessler RC. The costs of depression. Psychiatr Clin North Am 2012 Mar;35(1):1-14 [FREE Full text] [CrossRef] [Medline]
  7. Diagnostic and Statistical Manual of Mental Disorders, 5th edition. Washington, DC: American Psychiatric Publishing; 2013.
  8. Carey TA, Tai SJ, Mansell W, Huddy V, Griffiths R, Marken RS. Improving professional psychological practice through an increased repertoire of research methodologies: illustrated by the development of MOL. Prof Psychol Res Practice 2017 Jun;48(3):175-182. [CrossRef]
  9. Cuijpers P, Riper H, Andersson G. Internet-based treatment of depression. Current Opinion Psychol 2015 Aug;4:131-135. [CrossRef]
  10. Etzelmueller A, Vis C, Karyotaki E, Baumeister H, Titov N, Berking M, et al. Effects of internet-based cognitive behavioral therapy in routine care for adults in treatment for depression and anxiety: systematic review and meta-analysis. J Med Internet Res 2020 Aug 31;22(8):e18100 [FREE Full text] [CrossRef] [Medline]
  11. Karyotaki E, Ebert DD, Donkin L, Riper H, Twisk J, Burger S, et al. Do guided internet-based interventions result in clinically relevant changes for patients with depression? An individual participant data meta-analysis. Clin Psychol Rev 2018 Jul;63:80-92. [CrossRef] [Medline]
  12. Chan M, Jiang Y, Lee CY, Ramachandran HJ, Teo JY, Seah CW, et al. Effectiveness of eHealth-based cognitive behavioural therapy on depression: a systematic review and meta-analysis. J Clin Nurs 2022 Jan 20 (forthcoming). [CrossRef] [Medline]
  13. Schröder J, Berger T, Westermann S, Klein JP, Moritz S. Internet interventions for depression: new developments. Dialogues Clin Neurosci 2016 Jun;18(2):203-212 [FREE Full text] [Medline]
  14. Garrido S, Millington C, Cheers D, Boydell K, Schubert E, Meade T, et al. What works and what doesn't work? A systematic review of digital mental health interventions for depression and anxiety in young people. Front Psychiatry 2019 Nov 13;10:759 [FREE Full text] [CrossRef] [Medline]
  15. Loughnan SA, Joubert AE, Grierson A, Andrews G, Newby JM. Internet-delivered psychological interventions for clinical anxiety and depression in perinatal women: a systematic review and meta-analysis. Arch Womens Ment Health 2019 Dec 17;22(6):737-750. [CrossRef] [Medline]
  16. Tokgöz P, Hrynyschyn R, Hafner J, Schönfeld S, Dockweiler C. Digital health interventions in prevention, relapse, and therapy of mild and moderate depression: scoping review. JMIR Ment Health 2021 Apr 16;8(4):e26268 [FREE Full text] [CrossRef] [Medline]
  17. Berger T, Hämmerli K, Gubser N, Andersson G, Caspar F. Internet-based treatment of depression: a randomized controlled trial comparing guided with unguided self-help. Cogn Behav Ther 2011;40(4):251-266. [CrossRef] [Medline]
  18. Krämer R, Köhne-Volland L, Schumacher A, Köhler S. Efficacy of a web-based intervention for depressive disorders: three-arm randomized controlled trial comparing guided and unguided self-help with waitlist control. JMIR Form Res 2022 Apr 04;6(4):e34330 [FREE Full text] [CrossRef] [Medline]
  19. Musiat P, Johnson C, Atkinson M, Wilksch S, Wade T. Impact of guidance on intervention adherence in computerised interventions for mental health problems: a meta-analysis. Psychol Med 2022 Jan;52(2):229-240. [CrossRef] [Medline]
  20. Carlbring P, Andersson G, Cuijpers P, Riper H, Hedman-Lagerlöf E. Internet-based vs. face-to-face cognitive behavior therapy for psychiatric and somatic disorders: an updated systematic review and meta-analysis. Cogn Behav Ther 2018 Jan 07;47(1):1-18. [CrossRef] [Medline]
  21. Moher D, Liberati A, Tetzlaff J, Altman DG, PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. BMJ 2009 Jul 21;339(jul21 1):b2535 [FREE Full text] [CrossRef] [Medline]
  22. Tricco AC, Lillie E, Zarin W, O'Brien KK, Colquhoun H, Levac D, et al. PRISMA extension for scoping reviews (PRISMA-ScR): checklist and explanation. Ann Intern Med 2018 Oct 02;169(7):467-473 [FREE Full text] [CrossRef] [Medline]
  23. Rodriguez-Pulido F, Castillo G, Hamrioui S, Martin LD, Vazquez-Beltrán P, de la Torre-Díez I, et al. Treatment of depression in primary care with computerized psychological therapies: systematic reviews. J Med Syst 2020 Feb 13;44(3):67. [CrossRef] [Medline]
  24. Peters MD, Marnie C, Tricco AC, Pollock D, Munn Z, Alexander L, et al. Updated methodological guidance for the conduct of scoping reviews. JBI Evid Synth 2020 Oct;18(10):2119-2126. [CrossRef] [Medline]
  25. Arksey H, O'Malley L. Scoping studies: towards a methodological framework. Int J Soc Res Methodol 2005 Feb;8(1):19-32. [CrossRef]
  26. Andersson G, Carlbring P, Rozental A. Response and remission rates in internet-based cognitive behavior therapy: an individual patient data meta-analysis. Front Psychiatry 2019 Oct 25;10:749 [FREE Full text] [CrossRef] [Medline]
  27. Andersson G, Cuijpers P, Carlbring P, Riper H, Hedman E. Guided internet-based vs. face-to-face cognitive behavior therapy for psychiatric and somatic disorders: a systematic review and meta-analysis. World Psychiatry 2014 Oct 01;13(3):288-295 [FREE Full text] [CrossRef] [Medline]
  28. Watts S, van Ommeren M, Cuijpers P. Open access of psychological intervention manuals. World Psychiatry 2020 Jun 11;19(2):251-252 [FREE Full text] [CrossRef] [Medline]
  29. Xiang X, Wu S, Zuverink A, Tomasino KN, An R, Himle JA. Internet-delivered cognitive behavioral therapies for late-life depressive symptoms: a systematic review and meta-analysis. Aging Ment Health 2020 Aug 27;24(8):1196-1206 [FREE Full text] [CrossRef] [Medline]
  30. Martínez P, Rojas G, Martínez V, Lara MA, Pérez JC. Internet-based interventions for the prevention and treatment of depression in people living in developing countries: a systematic review. J Affect Disord 2018 Jul;234:193-200. [CrossRef] [Medline]
  31. Steffen A, Nübel J, Jacobi F, Bätzing J, Holstiege J. Mental and somatic comorbidity of depression: a comprehensive cross-sectional analysis of 202 diagnosis groups using German nationwide ambulatory claims data. BMC Psychiatry 2020 Mar 30;20(1):142 [FREE Full text] [CrossRef] [Medline]
  32. Kaufman J, Charney D. Comorbidity of mood and anxiety disorders. Depression and Anxiety 2020;12(S1):69-76 [FREE Full text] [CrossRef]
  33. Kalin NH. The critical relationship between anxiety and depression. Am J Psychiatry 2020 May 01;177(5):365-367. [CrossRef] [Medline]
  34. Rogers A, Wieman S, Baker A. Anxiety comorbidities: mood disorders, substance use disorders, and chronic medical illness. In: Clinical Handbook of Anxiety Disorders. Cham: Humana; 2020.
  35. Schmidt ID, Forand NR, Strunk DR. Predictors of dropout in internet-based cognitive behavioral therapy for depression. Cognit Ther Res 2019 Jun 16;43(3):620-630 [FREE Full text] [CrossRef] [Medline]
  36. Christensen H, Griffiths KM, Farrer L. Adherence in internet interventions for anxiety and depression. J Med Internet Res 2009 Apr 24;11(2):e13 [FREE Full text] [CrossRef] [Medline]
  37. Johansson O, Michel T, Andersson G, Paxling B. Experiences of non-adherence to Internet-delivered cognitive behavior therapy: a qualitative study. Internet Interv 2015 May;2(2):137-142 [FREE Full text] [CrossRef]
  38. Kaltenthaler E, Parry G, Beverley C, Ferriter M. Computerised cognitive-behavioural therapy for depression: systematic review. Br J Psychiatry 2008 Sep;193(3):181-184. [CrossRef] [Medline]
  39. van Ballegooijen W, Cuijpers P, van Straten A, Karyotaki E, Andersson G, Smit JH, et al. Adherence to Internet-based and face-to-face cognitive behavioural therapy for depression: a meta-analysis. PLoS One 2014;9(7):e100674 [FREE Full text] [CrossRef] [Medline]
  40. Barrett MS, Chua W, Crits-Christoph P, Gibbons MB, Casiano D, Thompson D. Early withdrawal from mental health treatment: implications for psychotherapy practice. Psychotherapy (Chic) 2008 Jun 01;45(2):247-267 [FREE Full text] [CrossRef] [Medline]
  41. Swift JK, Greenberg RP. Premature discontinuation in adult psychotherapy: a meta-analysis. J Consult Clin Psychol 2012 Aug;80(4):547-559. [CrossRef] [Medline]
  42. Beintner I, Vollert B, Zarski A, Bolinski F, Musiat P, Görlich D, et al. Adherence reporting in randomized controlled trials examining manualized multisession online interventions: systematic review of practices and proposal for reporting standards. J Med Internet Res 2019 Aug 15;21(8):e14181 [FREE Full text] [CrossRef] [Medline]
  43. Donkin L, Christensen H, Naismith SL, Neal B, Hickie IB, Glozier N. A systematic review of the impact of adherence on the effectiveness of e-therapies. J Med Internet Res 2011 Aug 05;13(3):e52 [FREE Full text] [CrossRef] [Medline]
  44. Treanor C, Kouvonen A, Lallukka T, Donnelly M. Acceptability of computerized cognitive behavioral therapy for adults: umbrella review. JMIR Ment Health 2021 Jul 06;8(7):e23091 [FREE Full text] [CrossRef] [Medline]
  45. Sieverink F, Kelders SM, van Gemert-Pijnen JE. Clarifying the concept of adherence to eHealth technology: systematic review on when usage becomes adherence. J Med Internet Res 2017 Dec 06;19(12):e402 [FREE Full text] [CrossRef] [Medline]
  46. Kelders SM, van Zyl LE, Ludden GD. The concept and components of engagement in different domains applied to ehealth: a systematic scoping review. Front Psychol 2020;11:926 [FREE Full text] [CrossRef] [Medline]
  47. Anjum RL, Copeland S, Rocca E. Medical scientists and philosophers worldwide appeal to to expand the notion of 'evidence'. BMJ Evid Based Med 2020 Feb 14;25(1):6-8. [CrossRef] [Medline]
  48. Radloff LS. The CES-D Scale: a self-report depression scale for research in the general population. Applied Psychol Measure 2016 Jul 26;1(3):385-401. [CrossRef]
  49. Spitzer R, Kroenke K, Williams JB. Validation and utility of a self-report version of PRIME-MD: the PHQ primary care study. Primary Care Evaluation of Mental Disorders. Patient Health Questionnaire. JAMA 1999 Nov 10;282(18):1737-1744. [CrossRef] [Medline]
  50. Montgomery SA, Asberg M. A new depression scale designed to be sensitive to change. Br J Psychiatry 1979 Apr;134:382-389. [CrossRef] [Medline]
  51. Sztein DM, Koransky CE, Fegan L, Himelhoch S. Efficacy of cognitive behavioural therapy delivered over the Internet for depressive symptoms: a systematic review and meta-analysis. J Telemed Telecare 2017 Jul 11;24(8):527-539. [CrossRef]
  52. Huguet A, Rao S, McGrath PJ, Wozney L, Wheaton M, Conrod J, et al. A systematic review of cognitive behavioral therapy and behavioral activation apps for depression. PLoS One 2016;11(5):e0154248 [FREE Full text] [CrossRef] [Medline]
  53. Arnberg F, Linton SJ, Hultcrantz M, Heintz E, Jonsson U. Internet-delivered psychological treatments for mood and anxiety disorders: a systematic review of their efficacy, safety, and cost-effectiveness. PLoS One 2014;9(5):e98118 [FREE Full text] [CrossRef] [Medline]
  54. Baumeister H, Reichler L, Munzinger M, Lin J. The impact of guidance on internet-based mental health interventions — a systematic review. Internet Interv 2014 Oct;1(4):205-215 [FREE Full text] [CrossRef]
  55. Davies E, Morriss R, Glazebrook C. Computer-delivered and web-based interventions to improve depression, anxiety, and psychological well-being of university students: a systematic review and meta-analysis. J Med Internet Res 2014 May 16;16(5):e130 [FREE Full text] [CrossRef] [Medline]
  56. Dowling M, Rickwood D. Online counseling and therapy for mental health problems: a systematic review of individual synchronous interventions using chat. J Technol Hum Serv 2013 Jan;31(1):1-21 [FREE Full text] [CrossRef]
  57. Fleming T, Cheek C, Merry SN, Thabrew H, Bridgman H, Stasiak K, et al. Juegos serios para el tratamiento o la prevención de la depresión: una revisión sistemática. Revista de Psicopatología y Psicología Clínica 2015 Jan 15;19(3):227 [FREE Full text] [CrossRef]
  58. Hedman E, Ljótsson B, Lindefors N. Cognitive behavior therapy via the Internet: a systematic review of applications, clinical efficacy and cost-effectiveness. Expert Rev Pharmacoecon Outcomes Res 2012 Dec;12(6):745-764 [FREE Full text] [CrossRef] [Medline]
  59. Königbauer J, Letsch J, Doebler P, Ebert D, Baumeister H. Internet- and mobile-based depression interventions for people with diagnosed depression: a systematic review and meta-analysis. J Affect Disord 2017 Dec 01;223:28-40 [FREE Full text] [CrossRef] [Medline]
  60. Lee E, Denison FC, Hor K, Reynolds RM. Web-based interventions for prevention and treatment of perinatal mood disorders: a systematic review. BMC Pregnancy Childbirth 2016 Feb 29;16:38 [FREE Full text] [CrossRef] [Medline]
  61. Li J, Theng YL, Foo S. Game-based digital interventions for depression therapy: a systematic review and meta-analysis. Cyberpsychol Behav Soc Netw 2014 Aug;17(8):519-527 [FREE Full text] [CrossRef] [Medline]
  62. Paganini S, Teigelkötter W, Buntrock C, Baumeister H. Economic evaluations of internet- and mobile-based interventions for the treatment and prevention of depression: a systematic review. J Affect Disord 2018 Jan 01;225:733-755 [FREE Full text] [CrossRef] [Medline]
  63. Păsărelu CR, Andersson G, Bergman Nordgren L, Dobrean A. Internet-delivered transdiagnostic and tailored cognitive behavioral therapy for anxiety and depression: a systematic review and meta-analysis of randomized controlled trials. Cogn Behav Ther 2017 Jan;46(1):1-28 [FREE Full text] [CrossRef] [Medline]
  64. Pennant M, Loucas CE, Whittington C, Creswell C, Fonagy P, Fuggle P, Expert Advisory Group. Computerised therapies for anxiety and depression in children and young people: a systematic review and meta-analysis. Behav Res Ther 2015 Apr;67:1-18 [FREE Full text] [CrossRef] [Medline]
  65. Rice S, Goodall J, Hetrick SE, Parker AG, Gilbertson T, Amminger GP, et al. Online and social networking interventions for the treatment of depression in young people: a systematic review. J Med Internet Res 2014 Sep 16;16(9):e206 [FREE Full text] [CrossRef] [Medline]
  66. Richards D, Richardson T. Computer-based psychological treatments for depression: a systematic review and meta-analysis. Clin Psychol Rev 2012 Jun;32(4):329-342 [FREE Full text] [CrossRef] [Medline]
  67. Rosenbaum S, Newby JM, Steel Z, Andrews G, Ward PB. Online physical activity interventions for mental disorders: a systematic review. Internet Interv 2015 May;2(2):214-220 [FREE Full text] [CrossRef]
  68. Saddichha S, Al-Desouki M, Lamia A, Linden IA, Krausz M. Online interventions for depression and anxiety - a systematic review. Health Psychol Behav Med 2014 Jan 01;2(1):841-881 [FREE Full text] [CrossRef] [Medline]
  69. Ye X, Bapuji SB, Winters SE, Struthers A, Raynard M, Metge C, et al. Effectiveness of internet-based interventions for children, youth, and young adults with anxiety and/or depression: a systematic review and meta-analysis. BMC Health Serv Res 2014 Jul 18;14:313-319 [FREE Full text] [CrossRef] [Medline]
  70. Ouzzani M, Hammady H, Fedorowicz Z, Elmagarmid A. Rayyan-a web and mobile app for systematic reviews. Syst Rev 2016 Dec 05;5(1):210 [FREE Full text] [CrossRef] [Medline]
  71. Cochrane Handbook for Systematic Reviews of Interventions. Hoboken, New Jersey, United States: John Wiley & Sons; 2019.
  72. Lindquist R, Wyman J, Talley K, Findorff M, Gross C. Design of control-group conditions in clinical trials of behavioral interventions. J Nurs Scholarsh 2007;39(3):214-221 [FREE Full text] [CrossRef] [Medline]
  73. Lambert JD, Greaves CJ, Farrand P, Price L, Haase AM, Taylor AH. Web-based intervention using behavioral activation and physical activity for adults with depression (the eMotion study): pilot randomized controlled trial. J Med Internet Res 2018 Jul 16;20(7):e10112 [FREE Full text] [CrossRef] [Medline]
  74. Geraedts AS, Kleiboer AM, Twisk J, Wiezer NM, van Mechelen W, Cuijpers P. Long-term results of a web-based guided self-help intervention for employees with depressive symptoms: randomized controlled trial. J Med Internet Res 2014 Jul 09;16(7):e168 [FREE Full text] [CrossRef] [Medline]
  75. Kladnitski N, Smith J, Uppal S, James MA, Allen AR, Andrews G, et al. Transdiagnostic internet-delivered CBT and mindfulness-based treatment for depression and anxiety: a randomised controlled trial. Internet Interv 2020 Apr;20:100310 [FREE Full text] [CrossRef] [Medline]
  76. Stiles-Shields C, Montague E, Kwasny MJ, Mohr DC. Behavioral and cognitive intervention strategies delivered via coached apps for depression: pilot trial. Psychol Serv 2019 May;16(2):233-238 [FREE Full text] [CrossRef] [Medline]
  77. Hoek W, Schuurmans J, Koot HM, Cuijpers P. Effects of internet-based guided self-help problem-solving therapy for adolescents with depression and anxiety: a randomized controlled trial. PLoS One 2012 Aug 31;7(8):e43485 [FREE Full text] [CrossRef] [Medline]
  78. Hunkeler EM, Hargreaves WA, Fireman B, Terdiman J, Meresman JF, Porterfield Y, et al. A web-delivered care management and patient self-management program for recurrent depression: a randomized trial. Psychiatr Serv 2012 Nov;63(11):1063-1071. [CrossRef] [Medline]
  79. Westerhof G, Lamers S, Postel M, Bohlmeijer E. Online therapy for depressive symptoms: an evaluation of counselor-led and peer-supported life review therapy. Gerontologist 2019 Jan 09;59(1):135-146. [CrossRef] [Medline]
  80. Titov N, Dear BF, Schwencke G, Andrews G, Johnston L, Craske MG, et al. Transdiagnostic internet treatment for anxiety and depression: a randomised controlled trial. Behav Res Ther 2011 Aug;49(8):441-452. [CrossRef] [Medline]
  81. Ström M, Uckelstam C, Andersson G, Hassmén P, Umefjord G, Carlbring P. Internet-delivered therapist-guided physical activity for mild to moderate depression: a randomized controlled trial. Peer J 2013;1:e178 [FREE Full text] [CrossRef] [Medline]
  82. Arjadi R, Nauta MH, Scholte WF, Hollon SD, Chowdhary N, Suryani AO, et al. Internet-based behavioural activation with lay counsellor support versus online minimal psychoeducation without support for treatment of depression: a randomised controlled trial in Indonesia. Lancet Psychiatry 2018 Sep;5(9):707-716. [CrossRef]
  83. Farrer L, Christensen H, Griffiths KM, Mackinnon A. Internet-based CBT for depression with and without telephone tracking in a national helpline: randomised controlled trial. PLoS One 2011 Nov 30;6(11):e28099 [FREE Full text] [CrossRef] [Medline]
  84. Sheeber LB, Seeley JR, Feil EG, Davis B, Sorensen E, Kosty DB, et al. Development and pilot evaluation of an internet-facilitated cognitive-behavioral intervention for maternal depression. J Consult Clin Psychol 2012 Oct;80(5):739-749 [FREE Full text] [CrossRef] [Medline]
  85. Wade S, Cassedy A, McNally K, Kurowski B, Kirkwood M, Stancin T, et al. A randomized comparative effectiveness trial of family-problem-solving treatment for adolescent brain injury: parent outcomes from the coping with head injury through problem solving (CHIPS) study. J Head Trauma Rehabil 2019;34(6):E1-E9. [CrossRef] [Medline]
  86. van der Zanden R, Kramer J, Gerrits R, Cuijpers P. Effectiveness of an online group course for depression in adolescents and young adults: a randomized trial. J Med Internet Res 2012 Jun 07;14(3):e86 [FREE Full text] [CrossRef] [Medline]
  87. Heller HM, Hoogendoorn AW, Honig A, Broekman BF, van Straten A. The effectiveness of a guided internet-based tool for the treatment of depression and anxiety in pregnancy (MamaKits online): randomized controlled trial. J Med Internet Res 2020 Mar 23;22(3):e15172 [FREE Full text] [CrossRef] [Medline]
  88. O'Mahen HA, Richards DA, Woodford J, Wilkinson E, McGinley J, Taylor RS, et al. Netmums: a phase II randomized controlled trial of a guided Internet behavioural activation treatment for postpartum depression. Psychol Med 2014 Jun;44(8):1675-1689 [FREE Full text] [CrossRef] [Medline]
  89. Ebert D, Nobis S, Lehr D, Baumeister H, Riper H, Auerbach R, et al. The 6-month effectiveness of Internet-based guided self-help for depression in adults with Type 1 and 2 diabetes mellitus. Diabet Med 2017 Jan;34(1):99-107 [FREE Full text] [CrossRef] [Medline]
  90. Fletcher S, Chondros P, Densley K, Murray E, Dowrick C, Coe A, et al. Matching depression management to severity prognosis in primary care: results of the Target-D randomised controlled trial. Br J Gen Pract 2021;71(703):e85-e94 [FREE Full text] [CrossRef] [Medline]
  91. Montero-Marín J, Araya R, Pérez-Yus MC, Mayoral F, Gili M, Botella C, et al. An internet-based intervention for depression in primary care in Spain: a randomized controlled trial. J Med Internet Res 2016 Aug 26;18(8):e231 [FREE Full text] [CrossRef] [Medline]
  92. Tulbure BT, Andersson G, Sălăgean N, Pearce M, Koenig HG. Religious versus conventional internet-based cognitive behavioral therapy for depression. J Relig Health 2018 Oct 24;57(5):1634-1648. [CrossRef] [Medline]
  93. Wilson M, Hewes C, Barbosa-Leiker C, Mason A, Wuestney KA, Shuen JA, et al. Engaging adults with chronic disease in online depressive symptom self-management. West J Nurs Res 2018 Jun 30;40(6):834-853. [CrossRef] [Medline]
  94. Sethi S, Campbell AJ, Ellis LA. The use of computerized self-help packages to treat adolescent depression and anxiety. J Technol Hum Serv 2010 Aug 31;28(3):144-160. [CrossRef]
  95. Hauffman A, Alfonsson S, Bill-Axelson A, Bergkvist L, Forslund M, Mattsson S, et al. Cocreated internet-based stepped care for individuals with cancer and concurrent symptoms of anxiety and depression: results from the U-CARE AdultCan randomized controlled trial. Psychooncology 2020 Dec 22;29(12):2012-2018 [FREE Full text] [CrossRef] [Medline]
  96. Kivi M, Eriksson MC, Hange D, Petersson E, Vernmark K, Johansson B, et al. Internet-based therapy for mild to moderate depression in Swedish primary care: short term results from the PRIM-NET randomized controlled trial. Cogn Behav Ther 2014;43(4):289-298 [FREE Full text] [CrossRef] [Medline]
  97. Hallgren M, Kraepelien M, Öjehagen A, Lindefors N, Zeebari Z, Kaldo V, et al. Physical exercise and internet-based cognitive-behavioural therapy in the treatment of depression: randomised controlled trial. Br J Psychiatry 2015 Sep 02;207(3):227-234. [CrossRef] [Medline]
  98. van der Zweerde T, van Straten A, Effting M, Kyle SD, Lancee J. Does online insomnia treatment reduce depressive symptoms? A randomized controlled trial in individuals with both insomnia and depressive symptoms. Psychol Med 2018 May 11;49(3):501-509. [CrossRef]
  99. Thompson NJ, Walker ER, Obolensky N, Winning A, Barmon C, Diiorio C, et al. Distance delivery of mindfulness-based cognitive therapy for depression: project UPLIFT. Epilepsy Behav 2010 Nov;19(3):247-254. [CrossRef] [Medline]
  100. Gilbody S, Brabyn S, Lovell K, Kessler D, Devlin T, Smith L, REEACT collaborative. Telephone-supported computerised cognitive-behavioural therapy: REEACT-2 large-scale pragmatic randomised controlled trial. Br J Psychiatry 2017 May;210(5):362-367. [CrossRef] [Medline]
  101. Do R, Lee S, Kim J, Cho M, Shin H, Jang M, et al. Effectiveness and dissemination of computer-based cognitive behavioral therapy for depressed adolescents: effective and accessible to whom? J Affect Disord 2021 Mar 01;282:885-893 [FREE Full text] [CrossRef] [Medline]
  102. Milgrom J, Danaher BG, Gemmill AW, Holt C, Holt CJ, Seeley JR, et al. Internet cognitive behavioral therapy for women with postnatal depression: a randomized controlled trial of MumMoodBooster. J Med Internet Res 2016 Mar 07;18(3):e54 [FREE Full text] [CrossRef] [Medline]
  103. Yang M, Jia G, Sun S, Ye C, Zhang R, Yu X. Effects of an online mindfulness intervention focusing on attention monitoring and acceptance in pregnant women: a randomized controlled trial. J Midwifery Womens Health 2019 Jan 29;64(1):68-77. [CrossRef] [Medline]
  104. Pugh NE, Hadjistavropoulos HD, Dirkse D. A randomised controlled trial of therapist-assisted, internet-delivered cognitive behavior therapy for women with maternal depression. PLoS One 2016;11(3):e0149186 [FREE Full text] [CrossRef] [Medline]
  105. Milgrom J, Danaher BG, Seeley JR, Holt CJ, Holt C, Ericksen J, et al. Internet and face-to-face cognitive behavioral therapy for postnatal depression compared with treatment as usual: randomized controlled trial of MumMoodBooster. J Med Internet Res 2021 Dec 08;23(12):e17185 [FREE Full text] [CrossRef] [Medline]
  106. Kim SC, Shaw BR, Shah DV, Hawkins RP, Pingree S, McTavish FM, et al. Interactivity, presence, and targeted patient care: mapping e-health intervention effects over time for cancer patients with depression. Health Commun 2019 Feb 14;34(2):162-171 [FREE Full text] [CrossRef] [Medline]
  107. Moeini B, Bashirian S, Soltanian A, Ghaleiha A, Taheri M. Examining the effectiveness of a web-based intervention for depressive symptoms in female adolescents: applying social cognitive theory. J Res Health Sci 2019 Aug 19;19(3):e00454 [FREE Full text] [Medline]
  108. Hudson JL, Moss-Morris R, Norton S, Picariello F, Game D, Carroll A, et al. Tailored online cognitive behavioural therapy with or without therapist support calls to target psychological distress in adults receiving haemodialysis: a feasibility randomised controlled trial. J Psychosom Res 2017 Nov;102:61-70. [CrossRef] [Medline]
  109. Norlund F, Wallin E, Olsson EM, Wallert J, Burell G, von Essen L, et al. Internet-based cognitive behavioral therapy for symptoms of depression and anxiety among patients with a recent myocardial infarction: the U-CARE heart randomized controlled trial. J Med Internet Res 2018 Mar 08;20(3):e88 [FREE Full text] [CrossRef] [Medline]
  110. Lundgren JG, Dahlström Ö, Andersson G, Jaarsma T, Kärner Köhler A, Johansson P. The effect of guided web-based cognitive behavioral therapy on patients with depressive symptoms and heart failure: a pilot randomized controlled trial. J Med Internet Res 2016 Aug 03;18(8):e194 [FREE Full text] [CrossRef] [Medline]
  111. Johansson P, Westas M, Andersson G, Alehagen U, Broström A, Jaarsma T, et al. An internet-based cognitive behavioral therapy program adapted to patients with cardiovascular disease and depression: randomized controlled trial. JMIR Ment Health 2019 Oct 03;6(10):e14648 [FREE Full text] [CrossRef] [Medline]
  112. van Luenen S, Garnefski N, Spinhoven P, Kraaij V. Guided internet-based intervention for people with HIV and depressive symptoms: a randomised controlled trial in the Netherlands. Lancet HIV 2018 Sep;5(9):e488-e497. [CrossRef]
  113. Nadort E, Schouten R, Boeschoten R, Smets Y, Chandie Shaw P, Vleming L, et al. Internet-based treatment for depressive symptoms in hemodialysis patients: a cluster randomized controlled trial. Gen Hosp Psychiatry 2022;75:46-53 [FREE Full text] [CrossRef] [Medline]
  114. Nygren T, Brohede D, Koshnaw K, Osman SS, Johansson R, Andersson G. Internet-based treatment of depressive symptoms in a Kurdish population: a randomized controlled trial. J Clin Psychol 2019 Jun 31;75(6):985-998. [CrossRef] [Medline]
  115. Hobfoll SE, Blais RK, Stevens NR, Walt L, Gengler R. Vets prevail online intervention reduces PTSD and depression in veterans with mild-to-moderate symptoms. J Consult Clin Psychol 2016 Jan;84(1):31-42. [CrossRef] [Medline]
  116. Palacios JE, Richards D, Palmer R, Coudray C, Hofmann SG, Palmieri PA, et al. Supported internet-delivered cognitive behavioral therapy programs for depression, anxiety, and stress in university students: open, non-randomised trial of acceptability, effectiveness, and satisfaction. JMIR Ment Health 2018 Dec 14;5(4):e11467 [FREE Full text] [CrossRef] [Medline]
  117. Staples LG, Fogliati VJ, Dear BF, Nielssen O, Titov N. Internet-delivered treatment for older adults with anxiety and depression: implementation of the Wellbeing Plus Course in routine clinical care and comparison with research trial outcomes. BJPsych Open 2016 Sep;2(5):307-313 [FREE Full text] [CrossRef] [Medline]
  118. Titov N, Fogliati VJ, Staples LG, Gandy M, Johnston L, Wootton B, et al. Treating anxiety and depression in older adults: randomised controlled trial comparing guided v. self-guided internet-delivered cognitive-behavioural therapy. BJPsych Open 2016 Jan;2(1):50-58 [FREE Full text] [CrossRef] [Medline]
  119. Titov N, Dear B, Ali S, Zou J, Lorian C, Johnston L, et al. Clinical and cost-effectiveness of therapist-guided internet-delivered cognitive behavior therapy for older adults with symptoms of depression: a randomized controlled trial. Behav Ther 2015 Mar;46(2):193-205 [FREE Full text] [CrossRef] [Medline]
  120. Tomasino K, Lattie E, Ho J, Palac H, Kaiser S, Mohr D. Harnessing peer support in an online intervention for older adults with depression. Am J Geriatr Psychiatry 2017 Oct;25(10):1109-1119 [FREE Full text] [CrossRef] [Medline]
  121. Boeschoten RE, Dekker J, Uitdehaag BM, Beekman AT, Hoogendoorn AW, Collette EH, et al. Internet-based treatment for depression in multiple sclerosis: a randomized controlled trial. Mult Scler 2017 Jul;23(8):1112-1122. [CrossRef] [Medline]
  122. Murphy M, Newby J, Butow P, Loughnan S, Joubert A, Kirsten L, et al. Randomised controlled trial of internet-delivered cognitive behaviour therapy for clinical depression and/or anxiety in cancer survivors (iCanADAPT Early). Psychooncology 2020 Jan;29(1):76-85 [FREE Full text] [CrossRef] [Medline]
  123. Braun L, Titzler I, Terhorst Y, Freund J, Thielecke J, Ebert D, et al. Effectiveness of guided internet-based interventions in the indicated prevention of depression in green professions (PROD-A): results of a pragmatic randomized controlled trial. J Affect Disord 2021 Jan 01;278:658-671 [FREE Full text] [CrossRef] [Medline]
  124. Ünlü Ince B, Cuijpers P, van 't Hof E, van Ballegooijen W, Christensen H, Riper H. Internet-based, culturally sensitive, problem-solving therapy for Turkish migrants with depression: randomized controlled trial. J Med Internet Res 2013 Oct 11;15(10):e227 [FREE Full text] [CrossRef] [Medline]
  125. Buhrman M, Syk M, Burvall O, Hartig T, Gordh T, Andersson G. Individualized guided internet-delivered cognitive-behavior therapy for chronic pain patients with comorbid depression and anxiety: a randomized controlled trial. Clin J Pain 2015 Jun;31(6):504-516. [CrossRef] [Medline]
  126. Salamanca-Sanabria A, Richards D, Timulak L, Connell S, Mojica Perilla M, Parra-Villa Y, et al. A culturally adapted cognitive behavioral internet-delivered intervention for depressive symptoms: randomized controlled trial. JMIR Ment Health 2020 Jan 31;7(1):e13392 [FREE Full text] [CrossRef] [Medline]
  127. Choi I, Zou J, Titov N, Dear B, Li S, Johnston L, et al. Culturally attuned Internet treatment for depression amongst Chinese Australians: a randomised controlled trial. J Affect Disord 2012 Feb;136(3):459-468 [FREE Full text] [CrossRef] [Medline]
  128. Newby J, Robins L, Wilhelm K, Smith J, Fletcher T, Gillis I, et al. Web-based cognitive behavior therapy for depression in people with diabetes mellitus: a randomized controlled trial. J Med Internet Res 2017 May 15;19(5):e157 [FREE Full text] [CrossRef] [Medline]
  129. Zagorscak P, Heinrich M, Sommer D, Wagner B, Knaevelsrud C. Benefits of individualized feedback in internet-based interventions for depression: a randomized controlled trial. Psychother Psychosom 2018 Jan 6;87(1):32-45. [CrossRef] [Medline]
  130. Andersson G, Hesser H, Veilord A, Svedling L, Andersson F, Sleman O, et al. Randomised controlled non-inferiority trial with 3-year follow-up of internet-delivered versus face-to-face group cognitive behavioural therapy for depression. J Affect Disord 2013 Dec;151(3):986-994 [FREE Full text] [CrossRef] [Medline]
  131. Rosso I, Killgore W, Olson E, Webb C, Fukunaga R, Auerbach R, et al. Internet-based cognitive behavior therapy for major depressive disorder: a randomized controlled trial. Depress Anxiety 2017 Mar;34(3):236-245 [FREE Full text] [CrossRef] [Medline]
  132. Lappalainen P, Langrial S, Oinas-Kukkonen H, Tolvanen A, Lappalainen R. Web-based acceptance and commitment therapy for depressive symptoms with minimal support: a randomized controlled trial. Behav Modif 2015 Nov;39(6):805-834. [CrossRef] [Medline]
  133. Blom K, Jernelöv S, Kraepelien M, Bergdahl M, Jungmarker K, Ankartjärn L, et al. Internet treatment addressing either insomnia or depression, for patients with both diagnoses: a randomized trial. Sleep 2015 Feb 01;38(2):267-277 [FREE Full text] [CrossRef] [Medline]
  134. Preschl B, Maercker A, Wagner B. The working alliance in a randomized controlled trial comparing online with face-to-face cognitive-behavioral therapy for depression. BMC Psychiatry 2011 Dec 06;11(1):189. [CrossRef]
  135. Wagner B, Horn A, Maercker A. Internet-based versus face-to-face cognitive-behavioral intervention for depression: a randomized controlled non-inferiority trial. J Affect Disord 2014 Jan;152-154:113-121 [FREE Full text] [CrossRef] [Medline]
  136. Kleiboer A, Donker T, Seekles W, van Straten A, Riper H, Cuijpers P. A randomized controlled trial on the role of support in Internet-based problem solving therapy for depression and anxiety. Behav Res Ther 2015 Sep;72:63-71 [FREE Full text] [CrossRef] [Medline]
  137. Kenter RM, Cuijpers P, Beekman A, van Straten A. Effectiveness of a web-based guided self-help intervention for outpatients with a depressive disorder: short-term results from a randomized controlled trial. J Med Internet Res 2016 Mar 31;18(3):e80 [FREE Full text] [CrossRef] [Medline]
  138. Høifødt RS, Lillevoll KR, Griffiths KM, Wilsgaard T, Eisemann M, Waterloo K, et al. The clinical effectiveness of web-based cognitive behavioral therapy with face-to-face therapist support for depressed primary care patients: randomized controlled trial. J Med Internet Res 2013 Aug 05;15(8):e153 [FREE Full text] [CrossRef] [Medline]
  139. Boele FW, Klein M, Verdonck-de Leeuw IM, Cuijpers P, Heimans JJ, Snijders TJ, Dutch Society for Neuro-Oncology (LWNO). Internet-based guided self-help for glioma patients with depressive symptoms: a randomized controlled trial. J Neurooncol 2018 Mar 13;137(1):191-203 [FREE Full text] [CrossRef] [Medline]
  140. Beiwinkel T, Eißing T, Telle N, Siegmund-Schultze E, Rössler W. Effectiveness of a web-based intervention in reducing depression and sickness absence: randomized controlled trial. J Med Internet Res 2017 Jun 15;19(6):e213 [FREE Full text] [CrossRef] [Medline]
  141. Smith J, Newby J, Burston N, Murphy M, Michael S, Mackenzie A, et al. Help from home for depression: a randomised controlled trial comparing internet-delivered cognitive behaviour therapy with bibliotherapy for depression. Internet Interv 2017 Sep;9:25-37 [FREE Full text] [CrossRef] [Medline]
  142. Mullin A, Dear B, Karin E, Wootton B, Staples L, Johnston L, et al. The UniWellbeing course: a randomised controlled trial of a transdiagnostic internet-delivered cognitive behavioural therapy (CBT) programme for university students with symptoms of anxiety and depression. Internet Interv 2015 May;2(2):128-136 [FREE Full text] [CrossRef]
  143. Dear B, Titov N, Schwencke G, Andrews G, Johnston L, Craske M, et al. An open trial of a brief transdiagnostic internet treatment for anxiety and depression. Behav Res Ther 2011 Dec;49(12):830-837 [FREE Full text] [CrossRef] [Medline]
  144. Karyotaki E, Klein AM, Ciharova M, Bolinski F, Krijnen L, de Koning L, et al. Guided internet-based transdiagnostic individually tailored Cognitive Behavioral Therapy for symptoms of depression and/or anxiety in college students: a randomized controlled trial. Behav Res Ther 2022 Mar;150:104028 [FREE Full text] [CrossRef] [Medline]
  145. Pots WT, Fledderus M, Meulenbeek PA, ten Klooster PM, Schreurs KM, Bohlmeijer ET. Acceptance and commitment therapy as a web-based intervention for depressive symptoms: randomised controlled trial. Br J Psychiatry 2016 Jan;208(1):69-77. [CrossRef] [Medline]
  146. Araya R, Menezes PR, Claro HG, Brandt LR, Daley KL, Quayle J, et al. Effect of a digital intervention on depressive symptoms in patients with comorbid hypertension or diabetes in Brazil and Peru: two randomized clinical trials. JAMA 2021 May 11;325(18):1852-1862 [FREE Full text] [CrossRef] [Medline]
  147. Boersma K, Södermark M, Hesser H, Flink IK, Gerdle B, Linton SJ. Efficacy of a transdiagnostic emotion-focused exposure treatment for chronic pain patients with comorbid anxiety and depression: a randomized controlled trial. Pain 2019 Aug;160(8):1708-1718 [FREE Full text] [CrossRef] [Medline]
  148. Brabyn S, Araya R, Barkham M, Bower P, Cooper C, Duarte A, et al. The second randomised evaluation of the effectiveness, cost-effectiveness and acceptability of computerised therapy (REEACT-2) trial: does the provision of telephone support enhance the effectiveness of computer-delivered cognitive behaviour therapy? A randomised controlled trial. Health Technol Assess 2016 Nov;20(89):1-64 [FREE Full text] [CrossRef] [Medline]
  149. Carlbring P, Hägglund M, Luthström A, Dahlin M, Kadowaki A, Vernmark K, et al. Internet-based behavioral activation and acceptance-based treatment for depression: a randomized controlled trial. J Affect Disord 2013 Jun;148(2-3):331-337. [CrossRef] [Medline]
  150. Day V, McGrath PJ, Wojtowicz M. Internet-based guided self-help for university students with anxiety, depression and stress: a randomized controlled clinical trial. Behav Res Ther 2013 Jul;51(7):344-351. [CrossRef] [Medline]
  151. Eriksson MC, Kivi M, Hange D, Petersson EL, Ariai N, Häggblad P, et al. Long-term effects of internet-delivered cognitive behavioral therapy for depression in primary care - the PRIM-NET controlled trial. Scand J Prim Health Care 2017 Jun;35(2):126-136 [FREE Full text] [CrossRef] [Medline]
  152. Flygare AL, Engström I, Hasselgren M, Jansson-Fröjmark M, Frejgrim R, Andersson G, et al. Internet-based CBT for patients with depressive disorders in primary and psychiatric care: is it effective and does comorbidity affect outcome? Internet Interv 2020 Mar;19:100303 [FREE Full text] [CrossRef] [Medline]
  153. Forand NR, Barnett JG, Strunk DR, Hindiyeh MU, Feinberg JE, Keefe JR. Efficacy of guided iCBT for depression and mediation of change by cognitive skill acquisition. Behav Ther 2018 Mar;49(2):295-307 [FREE Full text] [CrossRef] [Medline]
  154. Hadjistavropoulos HD, Peynenburg V, Nugent M, Karin E, Titov N, Dear BF. Transdiagnostic internet-delivered cognitive behaviour therapy with therapist support offered once-weekly or once-weekly supplemented with therapist support within one-business-day: pragmatic randomized controlled trial. Internet Interv 2020 Dec;22:100347 [FREE Full text] [CrossRef] [Medline]
  155. Hadjistavropoulos HD, Peynenburg V, Thiessen DL, Nugent M, Adlam K, Owens KM, et al. A pragmatic factorial randomized controlled trial of transdiagnostic internet-delivered cognitive behavioural therapy: exploring benefits of homework reflection questionnaires and twice-weekly therapist support. Internet Interv 2020 Dec;22:100357 [FREE Full text] [CrossRef] [Medline]
  156. Hadjistavropoulos HD, Schneider LH, Edmonds M, Karin E, Nugent MN, Dirkse D, et al. Randomized controlled trial of internet-delivered cognitive behaviour therapy comparing standard weekly versus optional weekly therapist support. J Anxiety Disord 2017 Dec;52:15-24 [FREE Full text] [CrossRef] [Medline]
  157. Johansson O, Bjärehed J, Andersson G, Carlbring P, Lundh LG. Effectiveness of guided internet-delivered cognitive behavior therapy for depression in routine psychiatry: a randomized controlled trial. Internet Interv 2019 Sep;17:100247 [FREE Full text] [CrossRef] [Medline]
  158. Johansson R, Björklund M, Hornborg C, Karlsson S, Hesser H, Ljótsson B, et al. Affect-focused psychodynamic psychotherapy for depression and anxiety through the internet: a randomized controlled trial. PeerJ 2013;1:e102 [FREE Full text] [CrossRef] [Medline]
  159. Johansson R, Ekbladh S, Hebert A, Lindström M, Möller S, Petitt E, et al. Psychodynamic guided self-help for adult depression through the internet: a randomised controlled trial. PLoS One 2012;7(5):e38021 [FREE Full text] [CrossRef] [Medline]
  160. Johansson R, Sjöberg E, Sjögren M, Johnsson E, Carlbring P, Andersson T, et al. Tailored vs. standardized internet-based cognitive behavior therapy for depression and comorbid symptoms: a randomized controlled trial. PLoS One 2012;7(5):e36905 [FREE Full text] [CrossRef] [Medline]
  161. Lappalainen P, Granlund A, Siltanen S, Ahonen S, Vitikainen M, Tolvanen A, et al. ACT internet-based vs face-to-face? A randomized controlled trial of two ways to deliver Acceptance and Commitment Therapy for depressive symptoms: an 18-month follow-up. Behav Res Ther 2014 Oct;61:43-54. [CrossRef] [Medline]
  162. Lindner P, Olsson EL, Johnsson A, Dahlin M, Andersson G, Carlbring P. The impact of telephone versus e-mail therapist guidance on treatment outcomes, therapeutic alliance and treatment engagement in internet-delivered CBT for depression: a randomised pilot trial. Internet Interv 2014 Oct;1(4):182-187. [CrossRef]
  163. Lindqvist K, Mechler J, Carlbring P, Lilliengren P, Falkenström F, Andersson G, et al. Affect-focused psychodynamic internet-based therapy for adolescent depression: randomized controlled trial. J Med Internet Res 2020 Mar 30;22(3):e18047 [FREE Full text] [CrossRef] [Medline]
  164. MacLean S, Corsi DJ, Litchfield S, Kucharski J, Genise K, Selaman Z, et al. Coach-facilitated web-based therapy compared with information about web-based resources in patients referred to secondary mental health care for depression: randomized controlled trial. J Med Internet Res 2020 Jun 09;22(6):e15001 [FREE Full text] [CrossRef] [Medline]
  165. Mira A, Bretón-López J, García-Palacios A, Quero S, Baños RM, Botella C. An Internet-based program for depressive symptoms using human and automated support: a randomized controlled trial. Neuropsychiatr Dis Treat 2017;13:987-1006 [FREE Full text] [CrossRef] [Medline]
  166. Mohr DC, Duffecy J, Ho J, Kwasny M, Cai X, Burns MN, et al. A randomized controlled trial evaluating a manualized TeleCoaching protocol for improving adherence to a web-based intervention for the treatment of depression. PLoS One 2013;8(8):e70086 [FREE Full text] [CrossRef] [Medline]
  167. Newby JM, Mackenzie A, Williams AD, McIntyre K, Watts S, Wong N, et al. Internet cognitive behavioural therapy for mixed anxiety and depression: a randomized controlled trial and evidence of effectiveness in primary care. Psychol Med 2013 Dec;43(12):2635-2648. [CrossRef] [Medline]
  168. Niles AN, Axelsson E, Andersson E, Hedman-Lagerlöf E, Carlbring P, Andersson G, et al. Internet-based cognitive behavior therapy for depression, social anxiety disorder, and panic disorder: effectiveness and predictors of response in a teaching clinic. Behav Res Ther 2021 Jan;136:103767. [CrossRef] [Medline]
  169. Nobis S, Lehr D, Ebert DD, Baumeister H, Snoek F, Riper H, et al. Efficacy of a web-based intervention with mobile phone support in treating depressive symptoms in adults with type 1 and type 2 diabetes: a randomized controlled trial. Diabetes Care 2015 May;38(5):776-783. [CrossRef] [Medline]
  170. Nyström MB, Stenling A, Sjöström E, Neely G, Lindner P, Hassmén P, et al. Behavioral activation versus physical activity via the internet: a randomized controlled trial. J Affect Disord 2017 Jun;215:85-93 [FREE Full text] [CrossRef] [Medline]
  171. Oehler C, Görges F, Rogalla M, Rummel-Kluge C, Hegerl U. Efficacy of a guided web-based self-management intervention for depression or dysthymia: randomized controlled trial with a 12-month follow-up using an active control condition. J Med Internet Res 2020 Jul 14;22(7):e15361 [FREE Full text] [CrossRef] [Medline]
  172. Reins JA, Boß L, Lehr D, Berking M, Ebert DD. The more I got, the less I need? Efficacy of internet-based guided self-help compared to online psychoeducation for major depressive disorder. J Affect Disord 2019 Mar 01;246:695-705. [CrossRef] [Medline]
  173. Richards D, Enrique A, Eilert N, Franklin M, Palacios J, Duffy D, et al. A pragmatic randomized waitlist-controlled effectiveness and cost-effectiveness trial of digital interventions for depression and anxiety. NPJ Digit Med 2020;3:85 [FREE Full text] [CrossRef] [Medline]
  174. Richards D, Timulak L, O'Brien E, Hayes C, Vigano N, Sharry J, et al. A randomized controlled trial of an internet-delivered treatment: its potential as a low-intensity community intervention for adults with symptoms of depression. Behav Res Ther 2015 Dec;75:20-31. [CrossRef] [Medline]
  175. Rollman BL, Herbeck Belnap B, Abebe KZ, Spring MB, Rotondi AJ, Rothenberger SD, et al. Effectiveness of online collaborative care for treating mood and anxiety disorders in primary care: a randomized clinical trial. JAMA Psychiatry 2018 Jan 01;75(1):56-64 [FREE Full text] [CrossRef] [Medline]
  176. Smith GC, Egbert N, Dellman-Jenkins M, Nanna K, Palmieri PA. Reducing depression in stroke survivors and their informal caregivers: a randomized clinical trial of a web-based intervention. Rehabil Psychol 2012 Aug;57(3):196-206 [FREE Full text] [CrossRef] [Medline]
  177. Titov N, Andrews G, Davies M, McIntyre K, Robinson E, Solley K. Internet treatment for depression: a randomized controlled trial comparing clinician vs. technician assistance. PLoS One 2010 Jun 08;5(6):e10939 [FREE Full text] [CrossRef] [Medline]
  178. Topooco N, Berg M, Johansson S, Liljethörn L, Radvogin E, Vlaescu G, et al. Chat- and internet-based cognitive-behavioural therapy in treatment of adolescent depression: randomised controlled trial. BJPsych Open 2018 Jul;4(4):199-207 [FREE Full text] [CrossRef] [Medline]
  179. Topooco N, Byléhn S, Dahlström Nysäter E, Holmlund J, Lindegaard J, Johansson S, et al. Evaluating the efficacy of internet-delivered cognitive behavioral therapy blended with synchronous chat sessions to treat adolescent depression: randomized controlled trial. J Med Internet Res 2019 Nov 01;21(11):e13393 [FREE Full text] [CrossRef] [Medline]
  180. Vernmark K, Lenndin J, Bjärehed J, Carlsson M, Karlsson J, Oberg J, et al. Internet administered guided self-help versus individualized e-mail therapy: a randomized trial of two versions of CBT for major depression. Behav Res Ther 2010 May;48(5):368-376. [CrossRef] [Medline]
  181. Dear BF, Fogliati VJ, Fogliati R, Johnson B, Boyle O, Karin E, et al. Treating anxiety and depression in young adults: A randomised controlled trial comparing clinician-guided versus self-guided Internet-delivered cognitive behavioural therapy. Aust N Z J Psychiatry 2018 Jul;52(7):668-679. [CrossRef] [Medline]
  182. Watts S, Mackenzie A, Thomas C, Griskaitis A, Mewton L, Williams A, et al. CBT for depression: a pilot RCT comparing mobile phone vs. computer. BMC Psychiatry 2013 Mar 07;13:49 [FREE Full text] [CrossRef] [Medline]
  183. Beck A, Steer R, Brown G. Beck depression inventory-II. Am Psychol Assoc 1996. [CrossRef]
  184. Perini S, Titov N, Andrews G. The climate sadness program of internet-based treatment for depression: a pilot study. E J Applied Psychol 2008 Dec 23;4(2):18-24. [CrossRef]
  185. Boot WR, Simons DJ, Stothart C, Stutts C. The pervasive problem with placebos in psychology: why active control groups are not sufficient to rule out placebo effects. Perspect Psychol Sci 2013 Jul;8(4):445-454. [CrossRef] [Medline]
  186. Depression in adults: recognition and management. National Institute for Health and Clinical Excellence. 2009 Oct 28.   URL: https://www.nice.org.uk/guidance/cg90 [accessed 2021-10-05]
  187. Keles S, Idsoe T. A meta-analysis of group Cognitive Behavioral Therapy (CBT) interventions for adolescents with depression. J Adolesc 2018 Aug;67:129-139 [FREE Full text] [CrossRef] [Medline]
  188. Li J, Zhang Y, Su W, Liu L, Gong H, Peng W, et al. Cognitive behavioral therapy for treatment-resistant depression: a systematic review and meta-analysis. Psychiatry Res 2018 Oct;268:243-250 [FREE Full text] [CrossRef] [Medline]
  189. Kessler RC, Birnbaum HG, Shahly V, Bromet E, Hwang I, McLaughlin KA, et al. Age differences in the prevalence and co-morbidity of DSM-IV major depressive episodes: results from the WHO World Mental Health Survey Initiative. Depress Anxiety 2010 Apr;27(4):351-364 [FREE Full text] [CrossRef] [Medline]
  190. Rosenthal R. The file drawer problem and tolerance for null results. Psychol Bull 1979 May;86(3):638-641. [CrossRef]


CBT: cognitive behavioral therapy
DSM-IV: Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition
PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses
PRISMA-ScR: Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews
RCT: randomized controlled trial
RQ: research question


Edited by J Torous; submitted 16.02.22; peer-reviewed by I Choi, A Coe; comments to author 06.05.22; revised version received 01.07.22; accepted 03.08.22; published 04.10.22

Copyright

©Line Børtveit, Anders Dechsling, Stefan Sütterlin, Tine Nordgreen, Anders Nordahl-Hansen. Originally published in JMIR Mental Health (https://mental.jmir.org), 04.10.2022.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in JMIR Mental Health, is properly cited. The complete bibliographic information, a link to the original publication on https://mental.jmir.org/, as well as this copyright and license information must be included.