Volume increases in putamen associated with positive symptom reduction in previously drug-naive schizophrenia after 6 weeks antipsychotic treatment.

BACKGROUND Brain structure appears to alter after antipsychotic administration, but it is unknown whether these alterations are associated with improvement of psychopathology in patients with schizophrenia. In this study, the authors explore this relationship. METHOD Altogether, 66 first-episode, drug-naive patients with schizophrenia and 23 well-matched healthy controls underwent brain magnetic resonance imaging scans at baseline. All 23 healthy controls and 42 of the patients were rescanned after 6 weeks follow-up. The patients received regular antipsychotic treatment during the 6-week period and their psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS) at baseline and 6 weeks. The difference in PANSS scores between baseline and 6 weeks was expressed as a ratio of the scores at baseline - 'PANSS reduction ratio'. A modified tensor-based morphometry procedure was applied to analyse longitudinal images. Correlations between regional volume changes, PANSS reduction ratio and antipsychotic drug dosages were explored. RESULTS Compared with healthy controls, there was a significant increase in grey-matter volume of the right putamen in patients after 6 weeks treatment. This volume change was positively correlated with a positive PANSS reduction score but not related to drug dosages. CONCLUSIONS Putaminal volume increased after 6 weeks antipsychotic treatment in first-episode schizophrenia. The increased volume was closely correlated with improved psychopathology, suggesting the putamen might be a biomarker to predict the treatment response in schizophrenia.