Abnormal intracellular calcium ion concentration in platelets and lymphocytes of bipolar patients

The authors measured intracellular Ca²⁺ concentrations in four manic and five bipolar depressed patients and seven comparison subjects. Platelet and lymphocyte intracellular Ca²⁺ concentrations were comparable. The patients' mean intracellular Ca²⁺ concentrations were higher than those of the comparison subjects and demonstrated more interindividual variation. These findings suggest a diffuse abnormality in mechanisms affecting intracellular calcium homeostasis in bipolar disorder.