Reduced catechol-O-methyltransferase activity in red blood cells of women with primary affective disorder.

Red blood cell catechol-O-methyltransferase, histamine-N-methyltransferase, and a methanol-forming enzyme were examined in a number of subjects with mental diseases. Catechol-O-methyltransferase activity was significantly reduced in female subjects with primary affective disorder (depression) as compared to normal women and men, men with primary affective disorder, and schizophrenic men and women. In depressed women, histamine-N-methyltransferase activity was elevated and the methanol-forming enzyme was unchanged.