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Date of Award


Degree Type

Dissertation (On-Campus Access Only)

Degree Name

Doctor of Psychology (PsyD)

Committee Chair

Paul Michael


Posttraumatic stress disorder is a multifaceted and widespread anxiety-related disorder associated with significant distress and functional impairment. Evidence has also revealed associations between PTSD and an increased risk for physical health problems, and PTSD has been considered the costliest anxiety-related disorder—largely due to non-psychiatric services such as emergency room visits. To mitigate the impacts of PTSD, decades of research has yielded efficacious treatments; in specific, prolonged exposure (PE)—a cognitive-behavioral treatment for PTSD—has the strongest body of empirical evidence, although is markedly underutilized in routine practice settings for both civilian and military populations. Given that the efficacy of PE is well-established, efforts should be focused on developing solutions to overcome barriers to its dissemination. To aid dissemination efforts, we conducted a meta-analytic review of effectiveness studies (N = 40) that examined the use of PE to treat PTSD within the context of a naturalistic setting. Results suggest that the mean effect size for reduction in PTSD symptoms at posttreatment across studies was large (Cohen’s d = 1.51; SE = .06) and significant (z = 24.83, p < .001). The mean effect size for reduction in comorbid depressive symptoms at posttreatment across studies (n = 28) was also large (Cohen’s d = 1.03; SE = .05) and significant (z = 19.17, p < .001). Altogether, the results of this systematic review found that PE—when administered within the context of a naturalistic setting—had a large and positive effect for decreasing self-reported symptoms of PTSD and comorbid depression. Furthermore, results from moderator analyses revealed that PE may yield smaller effects for reductions in (a) depressive symptoms for White patients and (b) PTSD symptoms for older patients. Results also indicated that the presence of a comorbid traumatic brain injury (TBI) may predict a larger decrease in PTSD symptoms at posttreatment when compared to those without a comorbid TBI. In general, results of this review suggested that PE was effective despite variations in study characteristics (e.g., use of five-session, 30 min session PE protocol), thereby suggesting that it is likely effective across patient populations, treatment adaptations, and study designs.

Available for download on Sunday, October 20, 2019