Randomized Controlled Trial of "Bounce Back Now," a Mobile App to Reduce Post-Disaster Symptoms of Posttraumatic Stress, Depressed Mood, and Sleep Disturbance.

OBJECTIVE There is tremendous public health interest in cost-efficient, scalable interventions to improve post-disaster mental health. The authors examined the efficacy of Bounce Back Now (BBN), a mobile application, versus an enhanced usual care app (EUC). METHODS A population-based trial was conducted with a diverse sample of 1,357 adults affected by Hurricane Harvey, Irma, Maria, Florence, or Michael in 2017 and 2018. Participants were eligible if they were ≥18 years of age, had access to an Internet-accessible device, were English speaking, and lived in a hurricane-affected area. BBN is designed to address symptoms of posttraumatic stress, depression, and sleep disturbance using evidence-based techniques grounded in behavioral and cognitive principles. Depressive, posttraumatic stress, and sleep symptoms were measured. RESULTS Participants' accessing of the BBN and EUC apps was similar. Active engagement was significantly greater among BBN users than EUC users (d=0.31), but BBN users engaged more actively in coping skills activities than in more time-intensive elements designed to promote behavior change. Moderate symptom reduction was observed in both conditions; Cohen's d values for the 3-month postbaseline assessment ranged from 0.49 to 0.60 in the BBN condition and from 0.36 to 0.41 in the EUC condition. Latent change models revealed that BBN users had significantly greater reductions in depression, sleep difficulty, and PTSD symptoms than EUC users, and these differences were maintained at the 6-month and 12-month postbaseline assessments. CONCLUSIONS Population impact is driven by reach and effectiveness. The potential reach of BBN is high, which heightens opportunity for population-level impact, but per-user symptom reduction was modest. Per-user impact may be improved by embedding digital health resources in the context of a broader health care strategy.