This project will develop objective, technology-based ways to measure mental health treatment response using data collected passively from smartphones and wearable devices. By adding these tools to an ongoing clinical trial of a meditation app for depression, the study will track changes in behavior, sleep, and body signals to identify reliable signs of improvement and support the development of faster, more practical measures of treatment response. Data collected under this award will be deidentified and housed in the ARPA-H EVIDENT Data Repository.