Limited clinical utility of urinary MHPG.

Ninety-five inpatient, RDC-diagnosed major depressives, 68 unipolar and 27 bipolar, underwent 72-hour urine collection for the measurement of 3-methoxy-4-hydroxyphenylglycol (MHPG). The average 24-hour urinary MHPG was compared by multivariate analysis of variance with the postdexamethasone cortisol (DST), the delta thyroid stimulating hormone (TRHST), six quantitative EEG (QEEG) measures of regional interhemispheric symmetry and six QEEG measures of focal frequency abnormalities. MHPG failed to discriminate between unipolar and bipolar II depression. It showed no significant correlations with postdexamethasone cortisol or delta TSH. It failed to correlate with QEEG regional coherence or with focal frequency abnormalities. MHPG covaries independently of other markers of depression.