PSYCHIATRIC MORBIDITY IN THE 1ST-DEGREE RELATIVES OF SCHIZOPHRENIC-PATIENTS

First-degree relatives (FDRs) of 1018 schizophrenic and 812 control pr obands were investigated. Psychiatric morbidity was present in 34.8% o f FDRs of schizophrenic probands and in 9.2% of FDRs of controls. Ther e was significantly more psychiatric illness in the siblings and paren ts than in the offspring of both schizophrenic and control subjects. T he morbidity risks for schizoid-schizotypal personality disorders, can nabis-use disorder and paranoid personality disorder were significantl y higher in the FDRs of schizophrenic patients than in those of contro ls, suggesting a biological relationship.