A geometric morphometric assessment of change in midline brain structural shape following a first episode of schizophrenia

Background: Previous reports indicate that brain structural abnormalities m ay be progressive in some patients with schizophrenia. Our study was design ed to determine deviations in the shape of midline brain structures at the lime of onset of symptoms of schizophrenia and 3-5 years Inter. Methods: Eleven landmarks were located on the midsagittal magnetic resonanc e imagery brain scans of 55 patients with schizophrenia and 22 nonpsychiatr ic control individuals. Geometric morphometric methods were used for the ex traction of shape variables from landmark coordinates. Permutation tests we re used to test the effects of gender, diagnosis, time elapsed since illnes s onset, and age on brain shape. Results: The diagnosis-by-time interaction and the effect of gender were si gnificantly different from zero (p < .027 and p < .039, respectively). The effect of time was significant in patients (p < .002), but nor in control s ubjects. Some anatomical abnormalities in mean patient brain morphology see m to be present both at the rime of diagnosis and at follow-up. These are s imilar to anomalies reported by previous geometric morphometrics studies, Conclusions: Some previously identified brain abnormalities are detectable at the time of first hospitalization. The rapid change in midline brain mor phology ill patients with schizophrenia during the subsequent 3-5 years is consistent with either a neurodegenerative disease process or an effect of treatment with psychiatric drugs. There is a sexual dimorphism in brain mor phology that might be reduced by schizophrenia. (C) 2000 Society of Biologi cal Psychiatry.