A number of neuropsychological models implicate disinhibition and a lack of response confidence in the pathogenesis of obsessive-compulsive disorder (OCD). To provide a fair test of the inhibition and confidence account, a variant of the directed forgetting (DF) paradigm with OCD-related and unrelated conditions was administered in 30 OCD patients and 20 healthy controls. First, 16 words were presented which the participant was subsequently instructed to forget. Then, 16 words were presented that should be memorized. After a short interval, patients were shown the to-be-forgotten and the to-be-remembered items along with new items in random order. The subjects were instructed to recollect both the to-be-remembered and the to-be-forgotten items. The subject was asked to grade responses according to confidence. In accordance with prior findings from our group, patients did not differ from controls on overall recollection, response confidence, and the recollection of to-be-forgotten (allegedly inhibited) information. Our study cannot refute the claim that disinhibition plays a role in OCD in view of the vast array of paradigms tapping different aspects of inhibition. Still, we deem a psychological understanding more fruitful that looks at dysfunctional coping strategies and false beliefs as mechanisms for the persistence and pervasiveness of obsessive thoughts.
