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

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychiatry

Background:

• The P300-P600 complex, particularly the P600 component, is linked to second-pass language processing and working memory (WM) operations.
• Dysfunction in brain regions like the anterior cingulate gyrus and basal ganglia, along with WM deficits, are implicated in the pathophysiology of obsessive-compulsive disorder (OCD).

Purpose of the Study:

• To investigate P600 event-related potential (ERP) activity during a WM task in individuals with OCD compared to healthy controls.
• To explore the relationship between P600 abnormalities, WM performance, and the neurobiological underpinnings of OCD.

Main Methods:

• Twenty drug-free OCD patients and 20 matched healthy controls participated.
• A computerized version of the Wechsler digit span test was administered.
• Auditory P600 was measured during the anticipatory period of the WM task.

Main Results:

• OCD patients demonstrated significantly enhanced P600 amplitudes in the right temporoparietal area compared to controls.
• Prolonged P600 latencies were observed in the right parietal region for the OCD group.
• Patients with OCD exhibited significantly impaired performance on the working memory task.

Conclusions:

• OCD patients show abnormal P600 amplitudes and latencies during a WM task, suggesting alterations in second-pass information processing.
• These neurophysiological findings may reflect underlying cognitive and neural deficits associated with OCD pathophysiology.
• The study highlights the potential of ERP measures, specifically P600, as biomarkers for cognitive dysfunction in OCD.