A new MMPI-derived indicator of liability to develop schizophrenia: evidence from the New York High-Risk Project.

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.

Attention, memory, and motor skills as childhood predictors of schizophrenia-related psychoses: the New York High-Risk Project.

OBJECTIVE: Childhood neurobehavioral deficits in offspring of schizophrenic, affectively ill, and psychiatrically normal parents were evaluated as predictors of schizophrenia-related psychoses in adulthood. METHOD: The offspring were tested with neurobehavioral measures at 7-12 years of age and assessed in mid-adulthood for axis I diagnoses. The relationships of childhood deficits in attention, verbal memory, and gross motor skills to adulthood schizophrenia-related psychoses were examined in separate path analyses by using logistic regression equations. Sensitivity and specificity were determined for each of the childhood dysfunctions. RESULTS: For the offspring of schizophrenic parents, childhood deficits in verbal memory, gross motor skills, and attention identified 83%, 75%, and 58%, respectively, of the subjects with schizophrenia-related psychoses; 50% were identified by all three variables combined. False positive rates in subjects who did not develop schizophrenia-related psychoses ranged from 18% for those with deficits in attention during childhood to 28% for those with deficits in memory. The three variables had low deficit rates in the offspring of the other two parental groups and were not associated with other psychiatric disorders in any group. CONCLUSIONS: 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.

The New York High-Risk Project. Prevalence and comorbidity of axis I disorders in offspring of schizophrenic parents at 25-year follow-up.

BACKGROUND: The New York High-Risk Project is a study of offspring of patients with schizophrenia (HRSz group) or affective illness (HRAff group) and psychiatrically normal parents (NC group) observed prospectively from childhood to adulthood. We herein present lifetime prevalence and comorbidity rates of Axis I disorders in subjects and their siblings from sample A of the project. METHODS: Schedule for Affective Disorders and Schizophrenia-Lifetime Version interviews conducted with the offspring in adulthood were used to obtain diagnoses of Axis I disorders. RESULTS: Schizophrenia and unspecified psychoses occurred only in the HRSz group. However, schizoaffective and psychotic affective disorders occurred equally in the HRSz and HRAff groups. Total rates of psychosis in these groups were significantly higher than in the NC group. All groups had similar rates of nonpsychotic affective and substance abuse disorders. The HRAff group, however, had significantly more total affective illness than the NC group and tended to have more anxiety disorders than the other groups. Comorbidity rates in the HRSz and HRAff groups were nearly twice those of the NC group. CONCLUSIONS: 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.

The New York High-Risk Project. Psychoses and cluster A personality disorders in offspring of schizophrenic parents at 23 years of follow-up.

BACKGROUND: We herein present lifetime prevalence rates of psychoses and DSM-III-R cluster A personality disorders in sample A of the New York High-Risk Project, a prospective study following offspring of parents with schizophrenia (HRSz subjects) and affective illness (HRAff subjects) and of psychiatrically normal parents (NC subjects) from midchildhood to adulthood. METHODS: We interviewed the offspring in adulthood with the Schedule for Affective Disorders and Schizophrenia, Lifetime Version, for Axis I disorders and the Personality Disorder Examination for Axis II disorders. RESULTS: Lifetime prevalence rates (+/- SE) of schizophrenia and unspecified psychosis were 11.1% +/- 4.3% and 5.6% +/- 3.1%, respectively, in the HRSz group and 0% in the HRAff and NC groups. Rates of schizoaffective disorder subclassified as mainly schizophrenic, however, were highest in the HRAff group. Rates of psychotic affective disorders did not differ between the HRSz and other groups. Age-corrected morbidity risks were similar to lifetime prevalence rates. Rates of the three cluster A personality disorders did not differ among the groups, but the combined rate was greater in the HRSz and HRAff groups than in the NC group. CONCLUSIONS: 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.