Inhibitory Neural Activity Predicts Response to Cognitive-Behavioral Therapy for Posttraumatic Stress Disorder

OBJECTIVE: Despite cognitive-behavioral therapy (CBT) being an effective treatment for posttraumatic stress disorder (PTSD), many patients do not respond to CBT. Understanding the neural bases of treatment response may inform treatment refinement, thereby improving treatment response rates. Adequate working memory function is proposed to enable engagement in CBT. METHOD: This study employed a Go/No-Go task to examine inhibitory function and its functional brain correlates as predictors of response to CBT in PTSD. Participants were recruited between October 2003 and May 2005. Thirteen treatment-seeking patients who met DSM-IV criteria for PTSD completed the Go/No-Go task while undergoing functional magnetic resonance imaging (fMRI), after which they entered 8 once-weekly sessions of CBT. PTSD severity was measured before treatment and again at 6 months following treatment completion using the Clinician-Administered PTSD Scale (primary outcome measure). RESULTS: After controlling for initial PTSD severity and ongoing depressive symptoms, greater activity in left dorsal striatal (Z = 3.19, P = .001) and frontal (Z = 3.03, P = .001) networks during inhibitory control was associated with lower PTSD symptom severity after treatment, suggesting better treatment response. CONCLUSIONS: These results suggest that neural circuitry underpinning inhibitory control plays a role in the outcome of CBT for patients with PTSD. TRIAL REGISTRATION: anzctr.org Identifier: ACTRN12610000017022.