Calcium function in affective disorders and healthy controls.

Calcium metabolism has been reported to be disturbed in some forms of affective disorder. We studied concurrently a battery of calcium measures in 29 unipolar, 14 bipolar depressed, 11 manic, and 10 healthy control subjects. In addition to measures of extracellular calcium, we studied intracellular calcium concentration in platelets and measures that reflect cellular capability to maintain a low intracellular Ca++ concentration in red blood cells (RBCs) and platelets. Plasma calcium was lower in unipolar and manic patients than in control subjects. Platelet calcium concentration was lower in unipolar than bipolar depressed patients. RBC Ca++ adenosine triphosphatase (ATPase) was lower in unipolar and control subjects than in bipolar depressed and manic patients. Platelet Ca++ ATPase and Ca++ uptake were inversely correlated with severity of illness in unipolar patients. In bipolar depressed patients, RBC Ca++ ATPase and platelet Ca++ uptake were inversely correlated with severity. In addition to indicating abnormalities in calcium activity in affective disorders, the data suggest that unipolar and bipolar patients differ in several measures and may have different pathophysiological disturbances in calcium metabolism.