Predictors of depression outcomes among university students following brief smartphone-based interventions.

Smartphone-delivered interventions offer a scalable solution for university students experiencing depression, yet outcomes remain inconsistent. This study examined predictors of depression remission and response in the AI-enhanced Vibe Up adaptive trial of brief smartphone-based interventions in 1282 Australian university students (mean age 23.52 years; 78.39% women) with elevated distress (Kessler-10 ≥ 20). After a two-week monitoring period, participants were randomised to two-week self-guided smartphone-based interventions targeting sleep hygiene, mindfulness, physical activity, or an ecological momentary assessment control intervention. Predictors of depression remission (DASS-21 in normal range) and response (≥50% reduction) were examined using hierarchical logistic regression. At post-intervention, 40.87% achieved remission and 29.88% showed response. Baseline depression severity, quality of life, general practitioner visits, and pre-intervention credibility predicted remission and/or response across all intervention arms. Higher baseline anxiety specifically predicted poorer remission in the sleep hygiene arm. Individual factors modestly predicted outcomes. Trajectory-based predictors may be needed to improve outcome prediction.