659. A RANDOMISED CONTROLLED TRIAL OF A SMARTPHONE APPLICATION AS AN EARLY INTERVENTION TO REDUCE SYMPTOMS OF DEPRESSION, ANXIETY AND POSTTRAUMATIC STRESS IN FIRST RESPONDERS

Abstract Background Many workforces are routinely exposed to traumatic events (e.g., firefighters) which can precipitate the development of depression, anxiety and posttraumatic stress symptoms. Timely early intervention is critical to alleviate mental health symptoms. Aims & Objectives This study aimed to evaluate the efficacy of an app-based version of the Skills for Life Adjustment and Resilience program (SOLAR-app) compared to an active control app (mood monitoring) in reducing symptoms of depression, anxiety and posttraumatic stress in a first responder organisation – firefighting. Method We conducted a two-arm, parallel group, triple-blind superiority randomized controlled trial. Firefighters (current or retired, N=163) who were experiencing psychosocial distress (scoring ≥7 on the Kessler 6) were recruited between June 2022 and May 2024. They were randomised into the SOLAR-app or the Mood Monitoring control app. The primary outcome was distress symptoms (total Hospital Anxiety Depression Scale (HADS)) at 8 weeks post baseline. Secondary outcomes included symptoms of depression (HADS Depression), anxiety (HADS Anxiety) and PTSD (PCL-5), and the secondary time point was 24 weeks. A constrained longitudinal data analysis (cLDA) model was used to analyze the primary outcome. Results There was a greater decrease in distress (total HADS) for those in the SOLAR-app group compared to those in the mood monitoring app group at 8 weeks. This represented a medium effect size (-0.47 with a 95% CI: -0.11 to -0.83). Compared to the mood monitoring app, the SOLAR-app resulted in a significantly greater 8 week decreases in symptoms of depression, anxiety and posttraumatic stress symptoms; and a significant greater decrease in depression at 24 weeks. Discussion & Conclusions The SOLAR-app was efficacious in reducing symptoms of depression, anxiety, and posttraumatic stress among firefighters. The SOLAR-app is a useful early intervention that is acceptable for firefighters, and potentially other high-risk professions.