(PS7-95) Examining Cognitive Change as a Mediator in Behavioral Activation Outcomes

Abstract Text: Behavioral activation (BA) is effective in the treatment of depression. However, the specific mechanisms within BA leading to improvement in depressive symptoms are not well understood. Although mechanisms such as change in environmental rewards have been proposed, research into their roles has produced weak results. One potential mechanism in BA that has received limited empirical attention is cognitive change (CC), a core process within the cognitive behavioral model. BA may exert an indirect effect on depressive symptoms by eliciting CC as a tool to test thoughts and beliefs. The current study investigated whether posttreatment CC mediated effects of pretreatment BA on posttreatment depressive symptoms in cognitive behavioral therapy (CBT) after covarying for baseline symptoms. Our sample included 26 clients with major depressive disorder who completed an 8-week course of group CBT. Clients completed measures of BA (Behavioral Activation for Depression Scale-Short Form), CC (Automatic Thoughts Questionnaire), and depressive symptoms (Patient Health Questionnaire-9). A mediation analysis was conducted with 10,000 bootstrapped samples. We found a significant total (B = -0.42, SE = 0.18, 95% CI [-0.80, -0.09]) and indirect effect (B = -0.30, SE = 0.15, 95% CI [-0.57, -0.06]), but not a significant direct effect (B = -0.13, SE = 0.19, 95% CI [0.53, -0.23]). Thus, the effects of baseline BA on posttreatment symptoms were fully mediated by posttreatment CC after controlling for baseline symptoms. The results suggest that BA may elicit symptom change through changes in cognition, highlighting the importance of cognitive change as a potential mechanism in BA.