Comparison of the clinical utility of the MMPI basic scales and specific MMPI state-trait scales: A test of Dahlstrom's hypothesis

Tested W. G. Dahlstrom's (1972) hypothesis that the clinical utility of the MMPI could be improved through the use of dimensionally pure personality trait and psychopathological state scales to supplant the present dimensionally complex clinical and validity scales. 508 male psychiatric patients (mean age, 37.7 yrs) were diagnostically categorized using a structured classification algorithm; discriminant functions were then computed first for a relatively untainted set of symptom, characterological, and validity scales, then for the basic MMPI clinical and validity scales as independent variates. Results fail to confirm Dahlstrom's hypothesis. The MMPI clinical scales distinguished diagnostic categories better than did the state and trait scales. Possible reasons for lack of confirmation of Dahlstrom's hypothesis are discussed, and alternative modes of analysis are suggested. (34 ref)