LATERALIZED ABNORMALITY OF HIGH-ENERGY PHOSPHATE-METABOLISM IN THE FRONTAL LOBES OF PATIENTS WITH BIPOLAR DISORDER DETECTED BY PHASE-ENCODED P-31-MRS

High energy phosphate metabolites were measured using phase-encoded in vivo phosphorus-31 magnetic resonance spectroscopy (P-31-MRS) in both the left and right frontal lobes of 25 patients with bipolar disorder . Eleven patients were examined in the depressive state, 12 in the man ic state, and 21 in the euthymic state. Twenty-one age-matched normal volunteers were also examined. The phosphocreatine (PCr) peak area per centage in the left frontal lobe in the patients in the depressive sta te was decreased compared with that in the normal controls. It was sig nificantly negatively correlated with the Hamilton Rating Scale for De pression score evaluated at the time of P-31-MRS examination. The PCr peak area percentage in the right frontal lobe in the patients in the manic and the euthymic states was decreased compared with that in the controls. These results are compatible with previous reports describin g reduction of glucose metabolism in the left frontal lobe in depressi ve patients with bipolar disorder and trait-dependent right hemisphere dysfunction in bipolar disorder.