DIURNAL ACTIVITY AND PULSATILITY OF THE HYPOTHALAMUS-PITUITARY-ADRENAL SYSTEM IN MALE DEPRESSED PATIENTS AND HEALTHY CONTROLS

There is only sparse and ambiguous information about circadian and pul satile secretion features of the hypothalamus-pituitary-adrenocortical system in depression;We studied 15 severely depressed (Hamilton Depre ssion Scale 30.4 +/- 6.7) male patients (age 22-72 yr; mean, 47.1 +/- 14.8) and 22 age-matched male controls (age 23-85 yr; mean, 53.1 +/- 1 8.2). Twenty-four-hour blood sampling from 0800-0800 h with 30-min sam pling intervals was performed; from 1800-2400 h, blood was drawn every 10 min. Multivariate analysis of covariance, with the covariate being age, revealed mean 24-h cortisol (315.9 +/- 58.5 vs. 188.2 +/- 27.3 n mol/L) and mean ACTH (7.82 +/- 1.94 vs. 5.79 +/- 1.28 pmol/L) to be si gnificantly increased in depressed patients. The frequency of cortisol (2.6 +/- 0.7 vs. 1.3 +/- 1.0 pulses/6 h) and ACTH (2.6 +/- 1.6 vs. 1. 6 +/- 1.4 pulses/6 h) pulses duping the evening were higher in patient s compared to controls. The flattened circadian cortisol variation and reduced time of quiescence of cortisol secretory activity (140 +/- 11 6 vs. 305 +/- 184 min) in patients suggest disturbances of circadian f unctions. We conclude that increased hypothalamus-pituitary-adrenocort ical activity in depression is related to a greater frequency of episo dic hormone release, and we hypothesize that the observed circadian ch anges might be partly due to altered mineralocorticoid and glucocortic oid receptor capacity and function.