The purpose of this study is to validate the effectiveness of using an integrated mobile sensing platform to deliver large-scale data-driven interventions to patients with depression.

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.

Inclusion Criteria:

• Currently suffering from depression (as measured by a PHQ-9 score of 10 or more at the time of screening)
• Own an iPhone or Android smartphone with a mobile voice calling plan with a US carrier
• Fluency in English

Exclusion Criteria:

• Participants with visual or hearing impairment
• Recent history of pregnancy (currently pregnant or those who have given birth within the past four months at the time of screening)
• Recent loss of a loved one (within the past two months at the time of screening)
• Unable or unwilling to accept End User License Agreement, or to provide information regarding their demographic characteristics and mental health history