PM467. White-matter alterations related to duration of untreated periods in patients with recent-onset psychosis.

Introduction: Duration of untreated periods (DUP) is one of the most important predictors of treatment outcome, prognosis of psychotic disorder. Also, most neuroimaging studies have investigated the gray matter changes and less attention has been paid to white matter. The object of this study is to focused on the microstructural integrity of more short DUP (<1000days) in a relatively large sample (n=89) of patients and correlation with symptom measures. Methods: 89 right-handed patients with recent-onset psychosis (schizophrenia and schizophreniform disorders) were enrolled this study. All patients were interviewed and diagnosed with the diagnostic criteria in Structured Clinical Interview for DSM-IV and examined by means of MRI at 3 Tesla at base line. Positive and Negative Syndrome Scale (PANSS), the Scale for the Assessment of Positive Symptoms (SAPS), and the Scale for the Assessment of Negative Symptoms (SANS) were administered at baseline, 2, 4 and 8 weeks after antipsychotic treatment. Fractional Anisotropy (FA) data were compared using tractbased spatial statistics (TBSS). Results: Correlation analysis in untreated patients with recentonset psychosis showed significant negative correlations between DUP and FA of left internal capsule, left anterior corona radiata and right posterior corona radiata in fronto-temporal white matter (p value < 0.05). Among the patients with recentonset psychosis, the FA values of superior corona radiata white matter in right frontal region showed trend-level significance of positive correlations with total scores of the SANS-B(p=0.916) at study baseline. Also, the FA values of body of corpus callosum white matter showed trend level positive correlation with total scores of the SAPS-B (p=0.924) at study baseline. Conclusion: The current study suggests that duration of untreated psychosis in patients with recent-onset psychosis may be associated with the brain micro structural change such as internal capsule and corona radiata in fronto-temporal regions.