The authors found that the mean urinary level of 3-methoxy-4-
hydroxyphenylglycol (MHPG) was significantly lower in 20 patients with
bipolar manic-depressive or schizoaffective depressions than in either 50
patients with unipolar depressions or 26 age- and sex-matched control
subjects. In contrast, the mean MHPG levels in the total group of patients
with unipolar depressions and in any subgroup defined by Research
Diagnostic Criteria (RDC) were not significantly different from control
values. However, examination of the distribution of urinary MHPG levels in
patients with unipolar depressions in relation to other recent findings by
the authors' collaborative research group suggested the existence of at
least three biochemical subtypes of unipolar depressions that may, in part,
be differentiated on the basis of urinary MHPG levels.Abstract Teaser