Fluid Distribution and the Response of Depression to E.C.T. and Imipramine

Abstract
Interest has been directed lately to the changes in sodium metabolism in depressive disorders, revealing a complex picture. Gibbons' finding (1960) that recovery with electroconvulsive therapy (E.C.T.) was associated with an apparent drop in total exchangeable sodium, was attributed by Coppen et al. (1962) to failure of his technique to allow for redistribution of sodium between body compartments. Their own work, allowing for different equilibration rates with isotopic sodium, showed no change in total exchangeable sodium during successful treatment with E.C.T., but did not exclude intercompartmental shifts. Coppen had in fact previously shown (1960) that the transfer of sodium from blood to cerebrospinal fluid is abnormally slow in depression, and is corrected during effective electroconvulsive therapy. Demonstration of significant shifts of electrolytes and fluid between, e.g., extracellular and intracellular spaces might thus cast light on important physiological factors in depressive illnesses.