Are trauma and dissociation related to treatment resistance in patients with obsessive-compulsive disorder?

Previous research has indicated a relation between obsessive-compulsive disorder (OCD), childhood traumatic experiences and higher levels of dissociation that appears to relate to negative treatment outcome for OCD. The aim of the present study is to investigate whether childhood trauma and dissociation are related to severity of OCD in adulthood. We also intend to examine the association between treatment resistance, dissociation, and each form of trauma. Participants included 120 individuals diagnosed with OCD; 58 (48.3 %) of them met the criteria for treatment-resistant OCD (resistant group), whereas the other 62 (51.7 %) were labeled as responder group. The intensity of obsessions and compulsions was evaluated using Yale-brown obsessive-compulsive scale (Y-BOCS). All patients were assessed with the traumatic experiences checklist, dissociative experiences scale, beck depression inventory, and beck anxiety inventory. Controlling for clinical variables, resistant group had significantly higher general OCD severity, anxiety, depression, trauma, and dissociation scores than the responders. Correlation analyses indicated that Y-BOCS scores were significantly related to severity of dissociation, anxiety, depression, and traumatic experiences. In a logistic regression analysis with treatment resistance as a dependent variable, high dissociation levels, long duration of illness, and poor insight emerged as relevant predictors, but gender, levels of anxiety, depression, and traumatic experiences did not. Our results suggest that dissociation may be a predictor of poorer treatment outcome in patients with OCD; therefore, a better understanding of the mechanisms that underlie this phenomenon may be useful. Future longitudinal studies are warranted to verify if this variable represents predictive factors of treatment non-response.