Symptom-specific EEG power correlations in patients with obsessive-compulsive disorder

Area of Science:

• Neuroscience
• Psychiatry
• Clinical Neurophysiology

Background:

• Obsessive-compulsive disorder (OCD) is associated with frontal cortical activity alterations.
• Previous neurophysiological studies in OCD yielded inconsistent results, possibly due to patient heterogeneity.

Purpose of the Study:

• To investigate quantitative electroencephalography (EEG) in unmedicated OCD patients compared to healthy controls.
• To correlate EEG findings with clinical variables, specifically obsessions and compulsions.

Main Methods:

• Quantitative EEG analysis was performed on 18 unmedicated OCD patients and 18 matched healthy controls.
• Mean frequency of background activity and absolute power in delta, theta, alpha, and beta bands were calculated.
• Correlations between EEG data and Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) sub-scores were analyzed.

Main Results:

• OCD patients exhibited a significantly lower mean frequency of EEG background activity, particularly at frontal electrodes.
• Increased delta power and decreased alpha/beta power were observed in OCD patients compared to controls.
• EEG power positively correlated with 'obsessions' and negatively with 'compulsions' sub-scores.

Conclusions:

• The study provides evidence for frontal cortical activity dysfunction in OCD.
• Opposite correlations of neurophysiological data with obsessions and compulsions suggest distinct pathophysiological mechanisms.