Evaluating the Acceptability and Feasibility of Collecting Passive Smartphone Data to Estimate Psychological Functioning in U.S. Service Members and Veterans: A Pilot Study.

This study examined the acceptability and feasibility of digital phenotyping—passive collection of smartphone screen interactions and typing kinematics via the Mindstrong Discovery app—in a military sample with a history of traumatic brain injury (TBI) and co-occurring psychological symptoms. Among 16 participants, 94% consented to install the app, with a 27% discontinuation rate primarily due to keyboard usability and technical issues affecting iPhone users. Data transfer was more complete and frequent among Android users compared to iOS users, reflecting technical challenges related to third-party keyboard requirements on iPhones. Exploratory machine learning models using phone and keyboard data predicted depression status and improvement with accuracy significantly better than chance. These findings suggest digital phenotyping is a promising, acceptable, and feasible tool for remote mental health monitoring in military populations, warranting further research with larger, more diverse samples.