[Monozygotic and dizygotic twins concordant with regard to schizophrenia]

The paper deals with a clinical study of schizophrenia in 30 pairs of concordant twins among which 10 were monozygotic, 5 pairs of a doubtful zygoticy and 16 dizygotic. Concordance to manifest schizophrenia was found in 62.5% of monozygotic twins and 25.5% in dizygotic. Both in monozygotic and in dizygotic pairs a constant coinciding sign, except the nozological belonging, was only the form of development in schizophrenia. The level of postive and negative disorders, the frequency of attacks and duration of remissions differes in monozygotic pairs insignificantly, in dizygotic-somewhat more. However, even in dizygotic pairs the similarities prevail over differences. It was possible to distinguish correlations between the traits of premorbid personality and the severity of the subsequent disease.