Underlying mechanisms of verbal memory deficits in obsessive-compulsive disorder and major depression--the role of cognitive self-consciousness.

BACKGROUND AND OBJECTIVES Previous studies have demonstrated that some individuals suffering from obsessive-compulsive disorder (OCD) are impaired in verbal memory performance. This study was designed to investigate the role of cognitive self-consciousness (CSC) as a putative underlying mechanism of these cognitive deficits. METHODS Verbal memory performance of 36 participants with OCD, 36 individuals with major depression disorder (MDD) and 36 healthy controls was assessed with the California Verbal Learning Test under three different experimental conditions: (1) single-task condition, (2) while simultaneously focusing on their thoughts (CSC condition), (3) while simultaneously focusing on external stimuli (dual-task condition). RESULTS Memory performance in the CSC condition and in the dual-task condition was reduced compared to single-task condition but no interaction effect was found. LIMITATIONS It remains unclear whether CSC and other concepts with an inward self-referential focus of attention (e.g. rumination) differ in the way they influence cognitive performance. CONCLUSIONS These results confirm the deteriorating influence of heightened CSC on verbal memory encoding but suggest that the effect is not specific to OCD.