| Abstract: | The purpose of this research is to study the differences between the Minnesota Multiphasic Personality Inventory (MMPI) and the MMPI-2 in psychiatric and substance use inpatients and to determine MMPI-2 profile characteristics related to program attrition by substance users. The MMPI-2 was administered to 198 substance users and 81 psychiatric patients 7- 10 days following hospital admission. Lower single scale elevations were noted for the MMPI-2 norms with the exception of scale L which was higher for both test versions. A difference of at least 5 T-score points between code type and the next highest scale elevation improved congruence between the test versions but resulted in the majority of profiles remaining unclassified. Psychiatric patients were more likely to elevate scales L, F, 8/Sc and 0/Si and have more profiles in the neurotic and psychotic categories than substance users. Substance users that were program noncompleters had higher elevations on scale L and more code classifications in the psychotic category. It is speculated that the relationship of scale F and program attrition is curvilinear. Patients with moderately elevated F scales were more likely to be program completers although those with invalid profiles (F>99T) were more likely to leave treatment early. The results question the equivalence of the MMPI and MMPI-2 with respect to spike profile and two-point code congruence, particularly when profiles are separated by at least 5 T-score points between code type and the next relative scale elevation. Reliance on interpretative strategies for the MMPI-2 that were originally developed for the MMPI is questionable. Configured interpretation, or knowledge of the differential effect of using the original or contemporary norms on spike and two-point code profiles, is recommended. |
|---|