Mechanisms of change in cognitive therapy for obsessive compulsive disorder: role of maladaptive beliefs and schemas.

The present study aimed to identify mechanisms of change in individuals with moderately severe obsessive-compulsive disorder (OCD) receiving cognitive therapy (CT). Thirty-six adults with OCD received CT over 24 weeks. At weeks 0, 4/6, 12, 16/18, and 24, independent evaluators assessed OCD severity, along with obsessive beliefs and maladaptive schemas. To examine mechanisms of change, we utilized a time-varying lagged regression model with a random intercept and slope. Results indicated that perfectionism and certainty obsessive beliefs and maladaptive schemas related to dependency and incompetence significantly mediated (improved) treatment response. In conclusion, cognitive changes in perfectionism/certainty beliefs and maladaptive schemas related to dependency/incompetence precede behavioral symptom reduction for OCD patients. Targeting these mechanisms in future OCD treatment trials will emphasize the most relevant processes and facilitate maximum improvement.