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 may be progressive in some patients with schizophrenia. Our study was designed to determine deviations in the shape of midline brain structures at the time of onset of symptoms of schizophrenia and 3-5 years later. METHODS Eleven landmarks were located on the midsagittal magnetic resonance imagery brain scans of 55 patients with schizophrenia and 22 nonpsychiatric control individuals. Geometric morphometric methods were used for the extraction of shape variables from landmark coordinates. Permutation tests were used to test the effects of gender, diagnosis, time elapsed since illness onset, and age on brain shape. RESULTS The diagnosis-by-time interaction and the effect of gender were significantly different from zero (p<.027 and p <.039, respectively). The effect of time was significant in patients (p <.002), but not in control subjects. Some anatomical abnormalities in mean patient brain morphology seem to be present both at the time of diagnosis and at follow-up. These are similar 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 morphology in 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 morphology that might be reduced by schizophrenia.