Psychometric indicators of liability to schizophrenia in children at genetic risk

Abstract

Psychometric signs derived from the Minnesota Multiphasic Personality Inventory (MMPI), which have been shown in prior research to be useful for identifying a schizophrenic phenotype, were evaluated as possible markers of transmissible liability to schizophrenia. Psychometric deviance was measured for 35 high-risk (HR) subjects at genetic risk for schizophrenia, 43 psychiatric comparison (PC) subjects at genetic risk for affective disorders, and 93 normal comparison (NC) subjects in the New York High-Risk Project, when the subjects were 13-26 years old. Twenty-three percent of the HR subjects, as compared to only 9% of PCs and 3% of NCs, displayed psychometric deviance. MMPI indicators had moderate sensitivity, specificity, and predictive power for discriminating subjects assessed by the Behavioral Global Adjustment Scale (BGAS) as phenotypically deviant. Since (1) a significantly higher percentage of subjects from the HR than either PC or NC groups appeared deviant on both the MMPI signs and the BGAS, (2) the convergence between the MMPI index and the BGAS was specific for risk to schizophrenia, and (3) the MMPI-deviant HRs could be qualitatively demarcated from the remaining HRs, PCs, and NCs, it was concluded that the MMPI indicators have specificity for identifying behavioral problems thought to reflect liability to schizophrenia.