[Neuroendocrine rhythms in uni- and bipolar depressions]

Eighteen patients with major depressive disorder of the endogenous subtype (8 unipolars and 10 bipolars) were submitted to blood sampling at 15 min interval for 24 h with polygraphic sleep recording during an acute episode of depression. Plasma growth hormone (GH), adrenocorticotrophin (ACTH) and cortisol were measured in each sample. The depressed patients hypersecreted GH during the daytime and had hypercortisolism which was evident throughout the 24 h span. The nadir of ACTH and cortisol rhythms was advanced by an average of 3 h as compared to the timing observed in normal subjects. These abnormalities were more pronounced and more consistent in patients with unipolar rather than bipolar depression. These results are consistent with the hypothesis that disorders of circadian time-keeping may characterize major endogenous depression.