MMPI-2 short form proposal: CAUTION

Abstract

The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) is widely used in neuropsychology, though its length (567 items) is sometimes prohibitive. This study investigated some psychometric characteristics of the 180-item version of the MMPI-2 ( Dahlstrom & Archer, 2000) in order to delineate its strengths, limitations, and appropriate scope of clinical application. Limited reliability and poor predictive accuracy were recently reported for many of the MMPI-2 short-form scales in a study that used 205 brain-injured patients. In the present investigation, we used a psychiatric sample ( N=186) with normal neurological findings to examine short-form accuracy in predicting basic scale scores, profile code types, identifying high-point scales, and classifying scores as pathological ( T≥65) or normal-range. The results suggest that, even as applied to neurologically normal individuals, the proposed short form of the MMPI-2 is unreliable for predicting clinical code types, identifying the high-point scale, or predicting the scores on most of the basic scales. In contrast, this short form can be used to predict whether the full-scale scores fall within the pathological range ( T≥65). These findings suggest that clinicians might be able to salvage a small amount of information from the shortened (180-item) version of the MMPI-2 when MMPI-2 protocols are incomplete. However, clinicians should not use a standard interpretive approach with this test, and routine clinical application is unwarranted. Future evaluations of short-form validity should provide a more detailed examination of individual protocols, including an analysis of the frequency of accurate prediction of full-form scores.