Psychophysiological and clinical value of event-related potentials in obsessive-compulsive disorder.

To investigate brain correlates of cognitive function in obsessive-compulsive disorder (OCD), event-related potentials (ERPs) were recorded in a group of thirteen unmedicated OCD patients and thirteen normal controls for verbal auditory stimuli in an oddball paradigm. The patients showed longer latencies of the N1 and P2, shorter latency of the P3, and reduced amplitude of the N2. These results suggest that OCDs stress the speed of task-dependent processes (i.e., by showing shorter N2 and P3 latencies) and have impairment of task-independent ones (i.e., by showing longer N1 and P2 latencies and reduced N2 amplitude). The components were more positive in the left hemisphere in OCDs and in the right hemisphere in normal controls. Future responders to treatment had significantly reduced N2 and enhanced P3 amplitudes relative to future nonresponders. So ERPs might provide psychophysiological profiles in OCDs with clinical and pharmacological implications.