Modern research criteria and the genetics of schizophrenia

Abstract

The relevance of narrowly defined diagnostic criteria to genetic research in schizophrenia in the nuclear families of 84 chronic schizophrenic probands compared with families of 90 normal control probands was assessed. The morbidity risk for narrowly defined schizophrenia in 1st-degree relatives of patients with the narrow diagnosis was significantly higher than the control rate (3.8% vs. 0.3%). The rate of chronic schizophrenia in the relatives of all schizophrenic patients was also significantly higher than the control rate (7.1% vs. 0.6%), as was the rate of spectrum disorders (33.4% vs. 11.3%). Familial transmission of narrowly defined schizophrenia is supported.