Amino acids in bipolar affective disorders: increased glycine levels in erythrocytes.

The authors measured the concentrations of 20 amino acids in the erythrocytes and plasma of 13 female bipolar patients and 10 female normal controls. The concentration of glycine in the erythrocyte was significantly elevated in the patient group. No differences were present in the plasma. Preliminary findings indicate that the high glycine levels were present in patients who were depressed, manic, or in remission and were unaffected by electroshock therapy.