Co-occurring PTSD in intensive OCD treatment: Impact on treatment trajectory vs. response

Background: Obsessive -compulsive disorder (OCD) and co-occurring posttraumatic stress disorder (PTSD) is associated with more severe and chronic OCD. However, findings regarding treatment effectiveness of cognitive behavioral treatment (CBT) with exposure and response prevention (ERP) with this comorbidity are mixed. Research aimed at understanding the precise barriers to OCD treatment effectiveness for individuals with cooccurring PTSD may help elucidate unique treatment needs. Methods: The current study used linear regression and latent growth curve analysis comparing treatment response and trajectory from patients with OCD ( n = 3083, 94.2 %) and OCD + PTSD ( n = 191, 5.2 %) who received CBT with ERP in two major intensive OCD treatment programs. Results: Although patients with OCD + PTSD evidenced similar trajectories of overall severity change, patients at one site required nearly 11 additional treatment days to achieve comparable reduction in OCD severity. Further, at the dimensional level, those with OCD + PTSD had poorer treatment response for unacceptable thoughts and symmetry symptoms. The moderate effect for unacceptable thoughts, indicating the widest gap in treatment response, suggests these symptoms may be particularly relevant to PTSD. Limitations: Findings are limited by a naturalistic treatment sample with variation in treatment provision. Conclusions: Findings emphasize caution in using a one -size -fits -all approach for patients with co-occurring OCD + PTSD within intensive OCD treatment programs, as broadly defined outcomes (e.g., reduction in overall severity) may not translate to reduction in the nuanced symptom dimensions likely to intersect with trauma. Unacceptable thoughts and symmetry symptoms, when co-occurring with PTSD, may require a trauma -focused treatment approach within intensive OCD treatment.