@Article{info:doi/10.2196/34898,
author="Zhang, Yuezhou
and Folarin, Amos A
and Sun, Shaoxiong
and Cummins, Nicholas
and Vairavan, Srinivasan
and Bendayan, Rebecca
and Ranjan, Yatharth
and Rashid, Zulqarnain
and Conde, Pauline
and Stewart, Callum
and Laiou, Petroula
and Sankesara, Heet
and Matcham, Faith
and White, Katie M
and Oetzmann, Carolin
and Ivan, Alina
and Lamers, Femke
and Siddi, Sara
and Vilella, Elisabet
and Simblett, Sara
and Rintala, Aki
and Bruce, Stuart
and Mohr, David C
and Myin-Germeys, Inez
and Wykes, Til
and Haro, Josep Maria
and Penninx, Brenda WJH
and Narayan, Vaibhav A
and Annas, Peter
and Hotopf, Matthew
and Dobson, Richard JB",
title="Longitudinal Relationships Between Depressive Symptom Severity and Phone-Measured Mobility: Dynamic Structural Equation Modeling Study",
journal="JMIR Ment Health",
year="2022",
month="Mar",
day="11",
volume="9",
number="3",
pages="e34898",
keywords="depression; mobile health; location data; mobility; dynamic structural equation modeling; mHealth; mental health; medical informatics; modeling",
abstract="Background: The mobility of an individual measured by phone-collected location data has been found to be associated with depression; however, the longitudinal relationships (the temporal direction of relationships) between depressive symptom severity and phone-measured mobility have yet to be fully explored. Objective: We aimed to explore the relationships and the direction of the relationships between depressive symptom severity and phone-measured mobility over time. Methods: Data used in this paper came from a major EU program, called the Remote Assessment of Disease and Relapse--Major Depressive Disorder, which was conducted in 3 European countries. Depressive symptom severity was measured with the 8-item Patient Health Questionnaire (PHQ-8) through mobile phones every 2 weeks. Participants' location data were recorded by GPS and network sensors in mobile phones every 10 minutes, and 11 mobility features were extracted from location data for the 2 weeks prior to the PHQ-8 assessment. Dynamic structural equation modeling was used to explore the longitudinal relationships between depressive symptom severity and phone-measured mobility. Results: This study included 2341 PHQ-8 records and corresponding phone-collected location data from 290 participants (age: median 50.0 IQR 34.0, 59.0) years; of whom 215 (74.1{\%}) were female, and 149 (51.4{\%}) were employed. Significant negative correlations were found between depressive symptom severity and phone-measured mobility, and these correlations were more significant at the within-individual level than the between-individual level. For the direction of relationships over time, Homestay (time at home) ($\phi$=0.09, P=.01), Location Entropy (time distribution on different locations) ($\phi$=−0.04, P=.02), and Residential Location Count (reflecting traveling) ($\phi$=0.05, P=.02) were significantly correlated with the subsequent changes in the PHQ-8 score, while changes in the PHQ-8 score significantly affected ($\phi$=−0.07, P<.001) the subsequent periodicity of mobility. Conclusions: Several phone-derived mobility features have the potential to predict future depression, which may provide support for future clinical applications, relapse prevention, and remote mental health monitoring practices in real-world settings. ",
issn="2368-7959",
doi="10.2196/34898",
url="https://mental.jmir.org/2022/3/e34898",
url="https://doi.org/10.2196/34898",
url="http://www.ncbi.nlm.nih.gov/pubmed/35275087"
}