Longitudinal studies of diurnal excretion patterns in two cases of cyclical affective disorder

Abstract

Longitudinal studies were made of the 12-hr (8 a.m.-8 p.m. and 8 p.m.-8 a.m.) urinary excretion of H 2O and electrolytes in 2 women with cyclical affective disorder—the first with an approximately 180-day cycle and the second with an approximately 39-day cycle. Dietary intake was fixed. In both cases, under controlled conditions, an upswing of mood was accompanied by highly significant decreases in the 24-hr urinary excretion of K and H 2O; there were no consistent changes in 24-hr urinary Na excretion. The changes in the urinary excretion of 24-hr K and H 2O were principally due to changes in the urinary excretion of day-time K and H 2O; the changes in night-time urinary excretion were either smaller or insignificant. From this data it can be argued that the diurnal variation of K and H 2O excretion in these patients varied inversely with the mood, being increased during depression and decreased during elation. Following these baseline observations, studies were carried out to clarify the relationship between the mood changes and the changes in excretion rhythms. These studies explored the role of the adrenal cortex and the effects of posture and activity changes. While the alterations in K diuresis appeared to be related to endogenous factors associated with mood rather than posture and activity changes, it could not be established definitely that the altered rhythms were due to changes in a central pacemaker. Firstly, the endocrine and neural control of renal circadian rhythms is still imperfectly understood. Secondly, the alterations in K diuresis might have reflected changes either in faecal K excretion or tissue K metabolism rather than changes in the neuroendocrine control of kidney function.