EFFECTS OF MONOAMINE-OXIDASE-A INHIBITION ON PLASMA BIOGENIC-AMINE METABOLITES IN DEPRESSED-PATIENTS

The main metabolites of noradrenalin, dopamine, and serotonin-3-methox y-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), and 5-hydroxy indoleacetic acid (5-HIAA), respectively-were estimated in plasma of 2 1 depressed patients before and after 2 and 4 weeks of treatment with the monoamine oxidase-type A (MAO-A) inhibitor moclobemide (mean final daily dose = 8.9 mg/kg body weight). The treatment caused significant mean reductions in plasma MHPG and HVA (46% and 30%, respectively), w hile plasma 5-HIAA was unchanged. Multiple regression analysis reveale d associations between reductions in MHPG and changes on the anxiety-s omatization factor of the Hamilton Rating Scale for Depression (HRSD), and between reductions in HVA and changes in the HRSD factors cogniti ve disturbance and retardation.