AI for Proactive Mental Health: A Multi-Institutional, Longitudinal Randomized Controlled Trial.

BACKGROUND: Young adults today face unprecedented mental health challenges, yet many hesitate to seek support owing to barriers such as accessibility, stigma, and time constraints. Bite-sized well-being interventions offer a promising solution to preventing mental distress before it escalates to clinical levels, but have not yet been delivered through personalized, interactive, and scalable technology. METHODS: We conducted the first multi-institutional, longitudinal, preregistered randomized controlled trial of a generative artificial intelligence (AI)-powered mobile app (Flourish) designed to address this gap. Over 6 weeks in the fall of 2024, 486 undergraduate students from three U.S. institutions were randomly assigned to receive app access or to a care-as-usual control condition. RESULTS: Participants instructed to use the Flourish app twice per week reported significantly greater resilience and social well-being (i.e., increased belonging, closeness to community, and reduced loneliness), and they were buffered against declines in positive affect, mindfulness, and flourishing. No significant condition-by-time effects were observed for depression, anxiety, or stress in this study with a general population. CONCLUSIONS: These findings suggest that, with purposeful and ethical design, generative AI can deliver proactive population-level well-being interventions that produce measurable benefits.