Comorbid posttraumatic stress disorder and major depressive disorder: The usefulness of a sequential treatment approach within a randomised design

Abstract

Cognitive Processing Therapy (CPT) and Behavioural Activation Therapy (BA) were used to treat individuals with comorbid posttraumatic stress disorder (PTSD) and major depressive disorder (MDD). Fifty-two individuals (48 women, 4 men) were randomized to CPT alone (n = 18), CPT then BA for MDD (n = 17), or BA then CPT (n = 17). Presenting trauma was primarily interpersonal (87 %). Participants were assessed at pre-, posttreatment, and 6-month follow-up. PTSD and MDD symptoms were the main outcome of interest; trauma cognitions, rumination, and emotional numbing were secondary outcomes. All groups showed sizeable reductions in PTSD and depression (effect sizes at follow-up ranging between 1.02-2.54). A pattern of findings indicated CPT/BA showed better outcomes in terms of larger effect sizes and loss of diagnoses relative to CPT alone and BA/CPT. At follow-up greater numbers of the CPT/BA group were estimated to have achieved good end-state for remission of both PTSD and depression (49 %, CI₉₅ [.26, .73]) relative to CPT alone (18 %, CI₉₅ [.03, .38]) and BA/CPT (11 %, CI₉₅ [.01, .29]). Although tempered by the modest sample size, the findings suggest that individuals with comorbid PTSD and MDD may benefit from having PTSD targeted first before remaining MDD symptoms are addressed.

Keywords: Cognitive processing therapy; Comorbidity; Interpersonal trauma; Major depressive disorder; Posttraumatic stress disorder.