Major Depressive Disorder (MDD) is one of the most common comorbidities among individuals with PTSD (APA, 2013). Despite evidence for this comorbidity, the specific conditions under which posttrauma symptoms confer risk for subsequent depression remain unclear. Research suggests that characteristics of the behavioral activation system (BAS) may impact the risk for depression (Johnson, Turner & Iwata, 2003), with differences in dimensions of BAS, namely, Reward Responsiveness (the degree to which an individual experiences positive responses to rewards), Drive (persistence in pursuing desired goals) and Fun-Seeking (strength of desires for new rewards and seeking rewards in the moment; Pickett et al., 2011) impacting the relation between PTSD and comorbid depression.
Aims of the current study were to determine the degree to which dimensions of behavioral approach influence the association of PTSD and depression. It was expected that PTSD would hold a stronger relation with depression in individuals lower on each of the BAS subscales and a weaker relation among individuals who are higher in these dimensions.
Participants were university undergraduates (N = 181) involved in an ongoing study evaluating functional outcomes following Criterion-A trauma. Posttrauma symptoms were examined using the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5). The Beck Depression Inventory – II (BDI-II) served as an index of depressive symptomatology whereas Carver and White’s (1994) BIS-BAS scales were used to assess different dimensions of behavioral activation. A series of independent regression models were used to examine the direct and interactive effects of PTSD and BAS Drive, Fun Seeking, and Reward Responsiveness scales on subsequent depression.
Unique effects of CAPS-5 (b = 10.55, p < .001) and BAS Reward (b = -.804, p = .008) were noted in the initial model although data failed to support a reliable interaction of these factors. In the subsequent model, only a unique effect of CAPS-5 (b=10.80, p < .001) was observed. Results of the final model indicated a reliable interaction of CAPS-5 and BAS Drive for depression (b=-.91, p=.049). Consistent with hypotheses, the relation between PTSD and depression was stronger among individuals low on BAS Drive (b=12.48, p < .001) and weaker among individuals with high scores on this scale (b=7.76, p < .001).
Shira Kern– Graduate Student, University of Wyoming, Laramie, Wyoming
Stephanie Stacy– University of Wyoming
Mary Lear– Graduate student, University of Wyoming, Laramie, Wyoming
Adam Ripley– Student, University of Wyoming, Laramie, Wyoming
Ryan Kozina– Doctoral Candidate, University of Wyoming
Joshua Clapp– Assistant Professor, University of Wyoming, Laramie, Wyoming