A prospective, observational, exploratory study collecting passive and active behavioral, environmental and physiological data, via the use of an Android smartphone application and Study Watch.~This sub-study is only open to sites participating in the RECOVER clinical study.~All subjects participating in the RECOVER clinical trial that currently own an Android smartphone will be offered participation in this sub-study.~Subjects who opt-in to the Mood App portion of the sub-study will be followed for a minimum of 12 months and a maximum of 60 months for the Mood App portion of the sub-study.~Subjects who also opt-in to the use of the Study Watch portion of the sub-study will be followed for a minimum of 12 months and maximum of 24 months for the Study Watch portion of the sub-study.
The objective of this study is to collect both active and passive data using a wearable, multi-sensor device (Verily Study Watch) and phone application (Mood App) which aims to capture mental health status, in subjects participating in the RECOVER clinical trial (A Prospective, Multi-center, Randomized Controlled Blinded Trial Demonstrating the Safety and Effectiveness of VNS Therapy® System as Adjunctive Therapy Versus a No Stimulation Control in Subjects With Treatment-Resistant Depression).