Feigning psychopathology among adolescent offenders: validation of the SIRS, MMPI-A, and SIMS.

Abstract

Clinical decision rules for the assessment of feigning and related response styles have not been systematically investigated in adolescent populations. For instance, evaluations of feigning on the Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A) involve cutting scores extrapolated from adult studies with the MMPI/MMPI-2. Such extrapolations are unwarranted because (a) adolescents perform differently than adults on MMPI/MMPI-2 validity scales and (b) the MMPI-A validity and clinical scales are substantively different than the MMPI/MMPI-2. Given the dearth of adolescent data, this study examined the clinical usefulness of three measures in the assessment of feigning: MMPI-A, Structured Interview of Reported Symptoms (SIRS), and Screening Index of Malingered Symptoms (SIMS). Employing a within-subjects analogue study on 53 dually diagnosed adolescent offenders, we found that commonly used MMPI-A scales (F, F1, and F2) were ineffective, but that F-K > 20 appeared promising. For the SIRS, classification of feigning based on adult criteria yielded moderate positive predictive poser and superb negative predictive power. As a screen, the SIMS proved to be moderately effective in identifying feigned protocols. Finally, two-stage discriminant analysis offered initial support of the incremental validity of a combined SIRS and MMPI-A evaluation of adolescent feigning.