A comparison of melatonin secretion in depressed patients and normal subjects

Depressed patients were carefully matched in pairs with normal subjects for the variables which are known to influence the secretion of melatonin in humans. In contrast to the previous literature, nocturnal melatonin secretion was not lower in the depressed group than in the normal group, and there was no difference in the timing of secretion; indeed, the trend was for greater melatonin secretion in the depressed group. The results are discussed in relation to previous studies, none of which has been so carefully controlled for the relevant variables.