REDUCTION OF BRAIN PHOSPHOCREATINE IN BIPOLAR-II DISORDER DETECTED BYP-31 MAGNETIC-RESONANCE SPECTROSCOPY

Brain phosphorus metabolism was measured by P-31-MRS in 15 patients wi th bipolar II disorder (BP II) and 14 patients with bipolar I disorder (BP I). Phosphocreatine (PCr)levels were significantly lower in patie nts with BP II in all three psychiatric states compared to 59 normal c ontrols (PCr (%) was 13.5 +/- 1.5 (mean +/- SD) for controls, and 12.2 +/- 1.7, 12.1 +/- 1.3, 12.0 +/- 1.9 for hypomanic, euthymic and depre ssed bipolar II patients respectively). High values of phosphomonoeste r (PME) were found in BP II patients in the hypomanic and depressive s tates, but PME values in the euthymic state did not differ significant ly from controls. Intracellular pH of BP II patients in all three psyc hiatric phases was similar to control values, whereas euthymic BP I pa tients had lower pH values. These results suggest that brain high ener gy phosphate metabolism may be impaired in BP II and that there may be pathophysiological differences between BP I and BP II.