Introduction: The effect of evidence-based post-traumatic stress disorder (PTSD) treatments on quality of life (QOL) is not well understood. In light of mixed findings on QOL after PTSD interventions, little is known about why some individuals experience functional and QOL improvements while others do not. This study examined treatment-related changes in depression, anger, and PTSD following cognitive processing therapy (CPT) as potential predictors of QOL change.

Materials and methods: Data from two randomized controlled trials, one examining CPT among female civilians and veterans (women's study NCT02362477; n = 126) and the other on CPT delivered to male veterans (men's study NCT00879255; n = 125), were used to test study aims. Linear mixed modeling examined changes in depression, anger, and PTSD as predictors of post-treatment QOL while controlling for baseline QOL. The VA Pacific Island Health Care System's Institutional Review Board approved all study procedures.

Results: Among women, reductions in depression from pre- to post-treatment had the strongest predictive value of post-treatment QOL (B = -1.15, 95% confidence interval (-1.71, -0.60), t = -4.07, P < .001). For men, reductions in trait anger from pre- to post-treatment predicted post-treatment QOL (B = -0.55, 95% confidence interval (-0.90, -0.19), t = -3.00, P = .003).

Conclusions: Improvements in QOL may be predicted by different symptoms for men and women following evidence-based PTSD treatment. Our findings suggest that change in depression symptoms is an important predictor of post-treatment QOL among women, while anger symptoms are more influential for men. QOL and functioning is underresearched within the context of PTSD treatment, and this study suggests that these domains should be examined within the context of gender.