Quantitative EEG analysis in obsessive compulsive disorder.

Quantitative analysis of the EEG (q-EEG) in patients with obsessive compulsive disorder (OCD) showed a decreased beta and an increased theta power at frontotemporal regions. The patients who had higher scores in doubting test (Maudsley Obsessive Compulsive Questionnaire) and more severely ill patients shared similar q-EEG features. The relative theta powers were significantly increased and alpha powers were significantly decreased in these patients, particularly in the frontotemporal region. It was suggested that the q-EEG may be useful in investigating the OCD patients with heterogeneous characteristics.