Memory and confidence in memory judgements among individuals with obsessive compulsive disorder and non-clinical controls.

The present study investigated episodic memory functioning in: (1) obsessive compulsive disorder (OCD) patients with primarily checking symptoms (i.e. checkers); (2) OCD patients without checking symptoms (i.e. non-checkers); and (3) non-clinical control participants. On a measure of recall, all groups were statistically equivalent with respect to the proportion of words correctly recalled. Using a recognition measure, checkers were unimpaired in episodic memory, as compared to non-checkers and non-clinical controls. However, relative to the other groups, patients with checking symptoms showed decreased confidence in their correct and incorrect recognition memory judgements, according to their item-by-item self-report confidence ratings. When checkers correctly identified previously seen words, they were also slower to respond than were the other groups, supporting the view that they were less confident in their memory judgments relative to the other groups, which did not differ on this measure. The results of the present study suggest that OCD checking is not related to memory impairments per se but rather that checking in OCD is a symptom of decreased confidence in memory.