Secondary outcomes of the guided self-help behavioral activation and physical activity for depression trial.

This article presents secondary outcome variables from a randomized controlled trial evaluating the efficacy of two guided self-help interventions for the treatment of depression: behavioral activation (BA) and physical activity (PA). Both interventions resulted in significant reductions in depressive symptoms compared to the wait-list control group, however the mechanisms by which these interventions influenced depression were not presented. The purpose of this paper was to compare changes in secondary outcome variables to gain insight into the mechanisms by which reactivation interventions reduce depressive symptoms. Mixed-model analysis of variances (ANOVAs) revealed significant increases in life satisfaction (Main effect: F = 4.63,  < 0.01) and self-efficacy (Main effect: F = 4.05,  < 0.01) as well as significant decreases in negative affect (Main effect:  =  5.24, < 0.01) and loneliness (Main effect:  =  7.49, < 0.01) in both interventions at pre-, mid-, post-intervention and follow-up. The group x time interactions were not significant, suggesting that the PA and BA interventions had comparable effects over time. These findings provide insight into the potential mechanisms underlying the effectiveness of guided self-help PA and BA interventions on depressive symptoms.