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

Abstract

Background: 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.

Purpose: 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.

Results: Mixed-model analysis of variances (ANOVAs) revealed significant increases in life satisfaction (Main effect: F_{(3, 91.71)} = 4.63, p < 0.01) and self-efficacy (Main effect: F_{(3, 91.32)} = 4.05, p < 0.01) as well as significant decreases in negative affect (Main effect: F_{(2, 75.88)} =  5.24, p < 0.01) and loneliness (Main effect: F_{(2, 71.78)} =  7.49, p < 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.

Conclusion: These findings provide insight into the potential mechanisms underlying the effectiveness of guided self-help PA and BA interventions on depressive symptoms.

Keywords:

• Behavioral activation
• physical activity
• depression
• affect
• life satisfaction
• self-efficacy
• loneliness

Notes

1 Positive affect is defined as feelings of pleasurable engagement (Watson et al., 1988)

2 Negative affect is defined as feelings of emotional distress (Watson et al., 1988).

3 Life satisfaction is the subjective assessment of one’s quality of life and is less fluctuating than affect (Pavot & Diener, 1993).

4 Physical activity is defined as any type of muscle movement that results in energy expenditure (Casperson et al., 1985).

5 Exercise is a component of physical activity that is planned, structured and repetitive with the aim of improving fitness, performance or health (Casperson et al., 1985).