Changes in blood plasma osmolality and states of mania.

Manic patients were studied systematically over a period of months. Fluctuations in their blood plasma osmolality were observed and these correlated significantly of and inversely with undulations in their mania rating scores. Successful treatment of patients with lithium carbonate was correlated with increasing levels of their plasma osmolality and with a significant remission of mania symptomatology. Animal studies have shown that adaptations to altered blood plasma osmolalities are accompanied by profound metabolic changes in tissues of the central nervous system. A similar relationship is likely to exist in man. We suggest, therefore, than an altered plasma osmolality is linked to changes in manic symptomatology, through osmotically regulated metabolic changes in the central nervous system.