“…Studies were grouped by analysis goal to allow for comparison of methods with similar objectives. To this end, to investigate our first research question we first compared studies that correlated individual passive smartphone features with depression symptom severity (Cao, et al, 2020; Sun, et al, 2023; Sverdlov, et al, 2021; Wasserzug, et al, 2023; Zhang, et al, 2022; Zou, et al, 2023). To address our second research question, we then shifted our focus to the different methods that have been used for various depression prediction tasks, investigating the methods used for predicting symptom severity (Braund, et al, 2022; Cao, et al, 2020; Faurholt-Jepsen, et al, 2022; Kathan, et al, 2022; Pedrelli, et al, 2020; Pellegrini, et al, 2022; Sverdlov, et al, 2021; Zhang, et al, 2021; Zhang, et al, 2022).…”