A comprehensive evaluation of a universal school-based depression prevention program for adolescents.

The present study proposes and demonstrates a comprehensive framework for evaluation of a universal school-based depression prevention program. Efficacy was evaluated by considering the impact of continuous versus categorical approaches to operationalizing outcome, the effect of the intervention on key change agent variables, and moderation of intervention effects by student symptom severity at baseline. Participants 252 adolescent boys and girls (60 % male), aged 13 to 17 years (M = 13.62 years, SD = 0.60 years) from four schools in the state of Victoria, Australia, who were allocated by school into a waitlist = control (n = 88) or a CBT-based intervention (n = 164) group. The intervention involved six 45-min weekly sessions run during wellbeing classes. While the intervention and control groups did not differ in average improvement in symptoms by post-intervention, further analyses showed that responsiveness was highly variable within the intervention, and those with elevated depressive symptoms benefitted most. The proposed change agents of self-esteem, resilience, body image satisfaction, and perceived social support did not uniquely predict change in depressive symptoms but collectively accounted for substantial variance in this change process. Collectively, this framework provided insights into aspects of the intervention that worked and highlighted areas for improvement, thus providing clear direction for future research.