The MMPI-A and 13-year-old inpatients: how young is too young?

This study examined two questions in the use of the MMPI-A with 13-year-old inpatients: (a) are the profiles of 13-year-old inpatients markedly different from those produced by 14-year-old inpatients, and (b) what is the effect of scoring with standard MMPI-A norms versus Archer MMPI-A norms for 13-year-olds. Protocols from 56 13-year-old and 85 14-year-old psychiatric inpatients were analyzed. No significant differences were found for age in mean T scores, and no clear pattern of differences was found in percentage of elevations into the clinical range (T 65) for validity, clinical, content, or supplemental scales. A strong multivariate effect was found with the use of Archer MMPI-A norms resulting in lower T-score values than when standard MMPI-A norms are used. However, univariate differences based on norms were not routinely found with statistically significant differences in only 2 of the 38 scales for males and 7 of the 38 scales for females. The two major exceptions to this finding were that the use of Archer norms versus standard MMPI-A norms resulting in significantly higher mean T scores and a significantly higher percentage of cases falling within the clinical range for Scale 1 and the depression content scale.