The effects of olanzapine treatment on brain regional glucose metabolism in neuroleptic-naive first-episode schizophrenic patients

ObjectiveThe current study examined metabolic alterations associated with a positive response to olanzapine and identified brain regions associated with treatment-related improvement of symptoms in neuroleptic-naive first-episode schizophrenic patients using [F-18]fluoro-deoxy-glucose positron emission tomography analysis. MethodsNeuroleptic-naive first-episode schizophrenic patients who showed good or poor clinical responses to olanzapine were assessed using the Positive and Negative Syndrome Scale. Data were analyzed using statistical nonparametric mapping. ResultsBefore treatment, responders showed significantly increased metabolism in the superior temporal gyrus and cerebellum compared with healthy controls. Glucose metabolism in responders was significantly increased after treatment in the left precentral gyrus, left postcentral gyrus, and left paracentral lobule, and significantly decreased in the left hypothalamus. An analysis of the Positive and Negative Syndrome Scale symptoms associated with olanzapine treatment revealed that suspiciousness/persecution scores were positively correlated with metabolic changes in the right superior frontal gyrus. ConclusionsThese findings provide evidence of the neural mechanisms underlying the effects of olanzapine on metabolism in the early stages of schizophrenia.