Nocturnal secretion of prolactin and cortisol and the sleep EEG in patients with major endogenous depression during an acute episode and after full remission.

We investigated the sleep electroencephalogram (EEG) and the nocturnal secretion of prolactin and cortisol in 25 normal subjects and 12 male inpatients with major depression before treatment and after remission and drug withdrawal. In the depressed patients, sleep-EEG disturbances persisted after recovery, whereas the cortisol concentration decreased. Prolactin variables in the patients did not differ between the two time points (i.e. before treatment and after remission). Compared with the normal subjects, the patients had significantly higher cortisol concentrations. The above findings were not altered when age was used as a covariate in statistical analysis. Our data suggest that neither depression nor aging exerts distinct effects on prolactin secretion.