The 24-hour pattern of urinary MHPG excretion in depressives and normals

The 24-h pattern of urinary 3-methoxy-4-hydroxy-phenylglycol (MHPG) was studied in 15 depressives and 15 healthy controls. MHPG was measured at 3-h intervals over two consecutive 24-h periods. The shape of the MHPG excretion pattern of the depressed group was different from that of the control group. However, both the consistency and shape of the individual 24-h MHPG patterns exhibited a high interindividual variability. Therefore it is difficult to speculate on a circadian phase difference between depressives and healthy controls. Major factors that may have influenced our results are discussed.