This study is a smartphone-based, randomized, single-blind, controlled parallel-
design study with two intervention arms and one control arm. The two intervention arms
will receive in-app messages and phone-based support, which will be triggered by
participant's self-reported surveys and passive behavioral data gathered through a
smartphone app. The study will include a nationwide sample of adult (18 years or older)
smartphone users, who are currently experiencing depressive symptoms. The primary
outcome will be decrease in depression symptom severity, as measured by the 9-item
Patient Health Questionnaire, over 6 months.
