Severe schizophrenics as a group show subtle abnormalities of cerebral structure. Cerebral ventricular enlargement is the best replicated finding, and this tends to be associated with impairment of neuropsychological performance. The idea that these abnormalities have a neurodevelopmental origin gains indirect support from the, admittedly less consistent, evidence of abnormalities of cerebral asymmetry and of neuronal migration in adult schizophrenics, as well as from the better established behavioural, psychomotor, and cognitive impairments reported in preschizophrenic children. However, the relationship between childhood and adult neuropsychological and brain structural findings has not been proven, and we don not know whether only some schizophrenia has a developmental origin, or whether patients differ only in the degree of developmental impairment that they show.