PRIMARY EARLY-ONSET DYSTHYMIA, BIOCHEMICAL CORRELATES OF THE THERAPEUTIC RESPONSE TO FLUOXETINE .2. URINARY METABOLITES OF SEROTONIN, NOREPINEPHRINE, EPINEPHRINE AND MELATONIN

The present study investigated pre- and post-treatment 24-h urinary me tabolites of monoamines and melatonin as a function of response to tre atment in primary early onset dysthymic patients. The main finding was that treatment responders had tower urinary 5-hydroxyindolacetic acid (5-HIAA) levels prior to treatment. Following treatment, urinary 5-HI AA tended to be decreased in nonresponders and increased in responders . As well, metanephrine levels were lower and 6-sulphatoxymelatonin le vels were higher in responders prior to treatment. These data support the view that there is a biological substrate for certain subgroups of dysthymia, part of which may involve serotonergic systems.