Average Risk of Developing Schizophrenia The risk of schizophrenia among biological relatives is greater for those with greater degrees of relatedness. An identical (MZ) twin of a twin with schizophrenia has a 48 percent risk of developing schizophrenia, for example, and offspring of two parents with schizophrenia have a 46 percent risk of developing the disorder.
(Adapted from Gottesman, 1991.)
(Adapted from Gottesman, 1991.)