Schizophrenia-related psychoses in adulthood are distinguished in subjects at risk for schizophrenia by childhood deficits in verbal memory, gross motor skills, and attention. The findings suggest that deficits in these variables are relatively specific to schizophrenia risk and may be indicators of the genetic liability to schizophrenia.

A large body of research indicates that the liability to develop schizophrenia is largely genetically mediated, although phenotypic expression requires environmental triggers/insults and/or epigenetic and/or stochastic factors. In an effort to identify the precise environmental factors that precipitate a predisposition to schizophrenia, researchers have implemented a high-risk model-the prospective study of offspring born to schizophrenic parents. As it is difficult to ascertain exactly which of the "high-risk" participants will actually develop the disorder, we examined the validity of an experimental MMPI scale, Schizophrenia Proneness (SzP), and the Moldin-Gottesman psychometric index to identify such individuals. Results suggest that the SzP scale can be an effective predictor of schizophrenia-related psychoses. A revised psychometric index is offered for further study.

The familial liabilities to schizophrenia and affective disorders show specificities and commonalities, differing markedly from each other in their expression of some disorders and sharing others. Patterns of comorbidity are generally, although not entirely, similar to these liabilities.

Our data strongly support a specific familial liability to narrowly defined schizophrenia that is not shared by families of probands with affective disorder. Schizoaffective disorder and cluster A personality disorders, however, occur in families of both schizophrenic probands and probands with affective disorder. Psychotic affective disorders, which are not increased in HRSz subjects, do not appear to be an expression of the liability to schizophrenia.

SummaryOne hundred and seventy-five offspring of parents in two psychiatrically ill groups and of normal controls in the New York High-Risk Project (NYHRP) were assessed for Axis II personality traits and disorders as defined by the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised (DSM-III-R). These offspring include: subjects at high risk for schizophrenia (HRSz, n = 48), all of whom have a parent with schizophrenic disorder; subjects at high risk for affective disorder (HRAff, n = 40), all of whom have a parent with affective disorder; and subjects at no increased risk for psychiatric illness (NC, n = 87), whose parents are psychiatrically normal.The trained interviewers, who administered a standardized direct interview, were blind to parental clinical status and to previous clinical status of the offspring.The rates for any personality disorder (PD) ranged from 7% to 20%. Comorbidity between Axis I and Axis II disorders was high for all groups.