Effect of age at onset of schizophrenia on white matter abnormalities.

BACKGROUND The pattern of brain morphological changes at the early stages of schizophrenia may depend on the age at onset of illness; in children and adolescents with schizophrenia, grey matter deficits are seen in the parietal lobe whereas in individuals with adult onset these are more widespread. AIMS To examine whether white matter is similarly affected. METHOD Diffusion tensor imaging was used to compare fractional anisotropy measures in individuals with adolescent-onset (n = 17) and adult-onset schizophrenia (n = 17) with those in age- and gender-matched controls. RESULTS Compared with their respective controls, individuals with adolescent-onset schizophrenia showed fractional anisotropy decrease in parietal regions; individuals with adult onset showed additional fractional anisotropy reductions in frontal, temporal and cerebellar regions. A differential effect of age at onset (adolescent v. adult) was noted bilaterally in medial prefrontal white matter. CONCLUSIONS White matter abnormalities in frontal regions in schizophrenia may depend on developmental stage at the time of illness onset.