MMPI predictors of mania among psychiatric inpatients

MMPI data from 64 patients with a diagnosis of manic-depressive illness, manic type, were compared with MMPI data from patients in two comparison groups--64 patients with a psychotic diagnosis other than manic-depressive illness, and 64 patients with a variety of psychiatric diagnoses. Manic patients had higher Ma scale scores for MMPI scales that assess personal distress and interpersonal difficulties (e.g., D and Si). Discriminant analysis, with the Ma, D, and Si scales as predictors, correctly classified as manic or not manic 82.5% of the patients in the derivation sample and 74.2% of the patients in the cross-validation sample. Two high-point pairs, Sc-Ma/Ma-Sc and Pa-Ma/Ma-Pa, occurred in the MMPI profiles of almost half of the manic patients but were rarely found among the profiles of other patients. The results of this study support the use of the MMPI in identifying manic patients, particularly when discriminating between mania and other types of psychosis.