Circadian Rhythms of Biogenic Amines in Health, Stress, and Depression

Biogenic amines such as epinephrine, norepinephrine, and serotonin (5-HT) exhibit a diurnal variation which seems to be related to the activity/rest phases. Besides 5-HT concentration 5-HT binding also shows a circadian rhythm which is inversely related to that of serotonin concentration. As can be shown for behavioral depression and stress, disturbances of the aminergic system reflect a health risk. Sleep deprivation, drugs like imipramine, inversion of the light/dark cycle, and immobilization stress affect the equilibrium of 5-HT concentration and 5-HT binding.