Psychosomatics and Chronobiology: Possible Implications of Neuroendocrine Rhythms

A Review

Abstract

 

Six of the variables involved in the psychoendocrine “catabolic-anabolic sequence” as defined by Mason--urinary corticosteroids, epinephrine, norepinephrine, aldosterone, urine volume and plasma growth hormone--undergo diurnal variations of large amplitude. Androgen secretion probably has, and estrogen, insulin and thyroid secretion may have, diurnal variations.

The organization of the daily neuroendocrine cycle differs in important respects from that of the psychoendocrine catabolic-anabolic sequence. Alteration of normal phase relations among endocrine rhythms could have an impact on overall hormone balance equal to or greater than that of psychoendocrine responses as usually understood. Such alterations could occur either as a result of unusual living schedules or of impaired capacity of the organism to synchronize its rhythms with environmental cycles. The capacity to synchronize internal rhythms with each other and with environmental cycles appears to involve higher nervous activity and to depend on structural and functional integrity of the brain.