Abnormal P600 in obsessive–compulsive disorder. A comparison with healthy controls

• Published in: Psychiatry research 2003-07, Vol.119 (1), p.133-143
• Main Authors: Papageorgiou, Charalabos C., Rabavilas, Andreas D.
• Format: Article
• Language: English
• Subjects: Adult; Adult and adolescent clinical studies; Anxiety disorders. Neuroses; Basal Ganglia - physiopathology; Biological and medical sciences; Diagnostic and Statistical Manual of Mental Disorders; Electrooculography; Event-related potentials; Evoked Potentials - physiology; Eye Movements - physiology; Female; Functional Laterality - physiology; Gyrus Cinguli - physiopathology; Humans; Male; Medical sciences; Memory Disorders - diagnosis; Memory Disorders - epidemiology; Obsessive-Compulsive Disorder - epidemiology; Obsessive-Compulsive Disorder - physiopathology; Obsessive-compulsive disorders; Obsessive–compulsive disorder; P600; Parietal Lobe - physiopathology; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Severity of Illness Index; Temporal Lobe - physiopathology; Wechsler Scales; Working memory
• ISSN: 0165-1781; 1872-7123
• DOI: 10.1016/S0165-1781(03)00109-4

Recently, the P600 component of the event-related potential (ERP), a waveform that is thought to be generated and/or modulated by the anterior cingulate gyrus and basal ganglia has been considered as an index of second pass-parsing processes of information processing, having much in common with working memory (WM) operation. Moreover, dysfunction of these brain structures as well as WM deficits have been implicated in the pathophysiology of obsessive–compulsive disorder (OCD). The present study is focused on P600 elicited during a WM test in OCD patients compared with healthy controls. Twenty drug-free OCD patients and an equal number of normal subjects matched for age, sex and educational level were studied via a computerized version of the Wechsler digit span test. Auditory P600 was measured during the anticipatory period of this test. The patient group, as compared with healthy controls, showed significantly enhanced amplitudes of P600 at the right temporoparietal area and prolonged latencies at the right parietal region. Moreover, the memory performance of patients was significantly impaired. These findings may indicate that OCD patients manifest abnormal aspects of second pass-parsing processes of information processing as they are reflected by P600 amplitudes and latencies.