We reported increased high-energy phosphate metabolism in the basal ganglia of antipsychotic-naïve schizophrenia patients using (31)P Magnetic Resonance Spectroscopy (MRS). These patients were followed up for 1 year and and reassessed using (31)P MRS. Fourteen (8 males) patients with DSM-IV schizophrenia and 14 (11 males) healthy controls underwent (31)P MRS of sub-cortical structures (predominantly basal ganglia) twice (mean+/-S.D. interscan interval 1.15+/-0.17year) on a 1.5T scanner. Total scores on the Positive and Negative Syndrome Scale (PANSS) decreased significantly after treatment in schizophrenia patients. Patients had significantly lower mean PCr/ATP ratios than healthy controls at baseline but not during the follow-up. In patients, there was a significant positive correlation between the magnitude of improvement in PANSS total scores and the extent of change in the PCr/ATP ratio. Findings support the hypothesis that reduction of energy demand or induction of decreased energy-demanding processes might underlie the mechanism of action of antipsychotics in schizophrenia. ; 75608