EPIDEMIOLOGIC AND CLINICAL CORRELATES OF FAMILIAL AND SPORADIC SCHIZOPHRENIA

We studied 68 schizophrenic cases with a schizophrenic first-degree re lative (familial group) and 62 cases without such a family history (sp oradic group). We compared them on: (i) clinical variables, including premorbid adjustment, age of onset and severity of symptoms; (ii) neur al abnormalities, including abnormal involuntary movements, neural ''s oft'' and ''hard signs''; (iii) neuropsychological tests, including th e Wechsler Adult Intelligence Scale and the Continuous Performance Tes t and (iv) environmental risk factors, including winter birth and obst etrical complications. Sporadic cases were more likely to be born in w inter and had more severe psychotic symptoms, but most analyses yielde d no difference between the groups. Our results offer some support tha t sporadic schizophrenia is a more environmental subtype, but they als o suggest that the familial vs sporadic distinction of schizophrenia h as limited power to identify distinct subgroups.