Baseline Cognitive Performance and Treatment Outcomes From Cognitive-Behavioral Therapies for Posttraumatic Stress Disorder: A Naturalistic Study

Abstract

Of troops returning from Iraq and Afghanistan, approximately 5–20% have PTSD, and another 11–23% have traumatic brain injury (TBI). Cognitive-behavioral therapies (CBTs) are empirically validated treatment strategies for PTSD. However, cognitive limitations may interfere with the ability to adhere to, and benefit from, CBTs. Co-morbid TBI has not been systematically taken into consideration in PTSD outcome research or in treatment planning guidance. We hypothesized that poorer pre-treatment cognitive abilities would be associated with poorer treatment outcomes from CBTs for PTSD. The present study was a naturalistic examination of "treatment as usual" in an outpatient clinic that provides manualized CBTs for PTSD to military service members and veterans. Participants were 23 veterans aged 18–50 years with combat-related PTSD and symptom duration more than 1 year; 16 of whom had mild TBI. Our predictor variables were well-normed objective tests of cognitive ability measured at baseline; our outcome variables were: a) individual slopes of change of the PTSD Checklist 5 (PCL-5) and the Clinician Assessment of PTSD Scale (CAPS-5) over weeks of treatment; and b) pre- to post-treatment change (Δ) in PCL-5 and CAPS-5. Contrary to our prediction, neither pre-treatment cognitive performance, nor the presence of co-morbid mild TBI, predicted poorer response to CBTs for PTSD. Our results discourage any notion of excluding PTSD patients with poorer cognitive ability from CBTs. Study limitations include a naturalistic treatment design, which did not allow for control of confounders, and an inability to completely rule out type II error because of small sample size.