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December 1968

Circadian Rhythm of Adrenal Cortical Activity in Depression: I. A Comparison of Depressed Patients With Normal Subjects

Author Affiliations

Marshfield, Wis
From the Marshfield Clinic and the Marshfield Clinic Foundation for Research and Education, Marshfield, Wis.

Arch Gen Psychiatry. 1968;19(6):674-681. doi:10.1001/archpsyc.1968.01740120034005

CIRCADIAN rhythms have been established for many physiological functions in both animals and humans.1 These include the well-known daily variations in body temperature and, of most interest to psychiatry, adrenal cortical activity.2 Although this circadian rhythm has been carefully investigated in normal subjects, it has been investigated in only a few pathological states including blindness,3 central nervous system (CNS) disease,4,5 and hypofunction and hyperfunction of the adrenals.2

A circadian rhythm of mood in depression has been known for many years. As most clinicians are aware, the depressed patient typically feels worse in the morning, and his mood improves as the day progresses. He generally feels well in evening and falls asleep without much difficulty. The depressed individual usually awakens early in the morning between 2 AM and 5 AM, feels very depressed, and is not able to go back to sleep. This