%0 Journal Article %@ 2368-7959 %I JMIR Publications %V 7 %N 6 %P e20513 %T Acceptability and Utility of an Open-Access, Online Single-Session Intervention Platform for Adolescent Mental Health %A Schleider,Jessica Lee %A Dobias,Mallory %A Sung,Jenna %A Mumper,Emma %A Mullarkey,Michael C %+ Department of Psychology, Stony Brook University, Psychology-B 340, Stony Brook, NY, 11794-2500, United States, 1 9174391872, jessica.schleider@stonybrook.edu %K internet intervention %K online interventions %K youth %K mental health %K adolescent %K depression %K single-session intervention %K intervention %D 2020 %7 30.6.2020 %9 Original Paper %J JMIR Ment Health %G English %X Background: Many youths with mental health needs are unable to access care. Single-session interventions (SSIs) have helped reduce youth psychopathology across multiple trials, promising to broaden access to effective, low-intensity supports. Online, self-guided SSIs may be uniquely scalable, particularly if they are freely available for as-needed use. However, the acceptability of online SSI and their efficacy have remained unexamined outside of controlled trials, and their practical utility is poorly understood. Objective: We evaluated the perceived acceptability and proximal effects of Project YES (Youth Empowerment & Support), an open-access platform offering three online SSIs for youth internalizing distress. Methods: After selecting one of three SSIs to complete, participants (ages 11-17 years) reported pre- and post-SSI levels of clinically relevant outcomes that SSIs may target (eg, hopelessness, self-hate) and perceived SSI acceptability. User-pattern variables, demographics, and depressive symptoms were collected to characterize youths engaging with YES. Results: From September 2019 through March 2020, 694 youths accessed YES, 539 began, and 187 completed a 30-minute, self-guided SSI. SSI completers reported clinically elevated depressive symptoms, on average, and were diverse on several dimensions (53.75% non-white; 78.10% female; 43.23% sexual minorities). Regardless of SSI selection, completers reported pre- to post-program reductions in hopelessness (dav=0.53; dz=0.71), self-hate (dav=0.32; dz=0.61), perceived control (dav=0.60; dz=0.72) and agency (dav=0.39; dz=0.50). Youths rated all SSIs as acceptable (eg, enjoyable, likely to help peers). Conclusions: Results support the perceived acceptability and utility of open-access, free-of-charge SSIs for youth experiencing internalizing distress. Trial Registration: Open Science Framework; osf.io/e52p3 %M 32602846 %R 10.2196/20513 %U http://mental.jmir.org/2020/6/e20513/ %U https://doi.org/10.2196/20513 %U http://www.ncbi.nlm.nih.gov/pubmed/32602846