Examining reward-seeking, negative self-beliefs and over-general autobiographical memory as mechanisms of change in classroom prevention programs for adolescent depression

BACKGROUND: Effective methods to prevent adolescent depressive symptoms could reduce suffering and burden across the lifespan. However, psychological interventions delivered to adolescents show efficacy only in symptomatic or high-risk youth. Targeting causal risk factors and assessing mechanistic change can help devise efficacious universal or classroom based prevention programs. METHODS: A non-randomized longitudinal design was used to compare three classroom-based prevention programs for adolescent depression (Behavioral Activation with Reward Processing, “Thinking about Reward in Young People” (TRY); Cognitive Behavioral Therapy (CBT) and Mindfulness Based Cognitive Therapy (MBCT)), and determine cognitive mechanisms of change in these programs. Cognitive mechanisms examined were reward-seeking, negative self-beliefs (assessed with behavioral tasks) and over-general autobiographical memory. 256 healthy adolescents aged 13–14 participated with 236 (92%) and 227 (89%) completing the pre- and post-assessments. RESULTS: TRY was the only intervention associated with a reduction in depressive symptoms at follow-up. Reward-seeking increased following TRY. In the other programs there were non-significant changes in cognitive mechanisms, with more reflective negative self-beliefs in CBT and fewer over-general autobiographical memories in MBCT In the TRY program, which focused on increasing sensitivity to rewarding activities, reward seeking increased and this was associated with decreased depressive symptoms. LIMITATIONS: Due to the infeasibility of a cluster randomized controlled trial, a non-randomized design was used. CONCLUSIONS: Increased reward-seeking was associated with decreased depressive symptoms and may be a mechanism of depressive symptom change in the intervention with a focus on enhancing sensitivity and awareness of reward. This study provides preliminary evidence to suggest that incorporating activities to enhance reward sensitivity may be fruitful in randomized controlled trials of universal prevention programs for depression.