Utility of the MMPI-168 with adolescents

Investigated the utility of the MMPI-168 with an adolescent psychiatric sample of 110 Ss by comparing published conversion values for adults to population-specific derived equations developed through both regression and substitution methods. Data analyses for the three equations compared 168 T scores to long-form scores via correlation coefficients and t-tests of mean scale score differences. The ability of the 168 to make accurate decisions with regard to profile validity, degree of elevation, high points, code typing, and diagnosis also was examined. Results that used the published equations were similar to those of previous 168 studies with adults. Although population-specific conversion equations produced means and standard deviations that more closely approximated the full MMPI, they failed to produce higher T score correlations or better prediction of profile validity and code-types than the published values. Appropriate uses and limitations of the 168 with adolescents are discussed.