Assessment of PTSD and Trauma Symptoms With the MMPI–3 in College Students: Validity and Incremental Utility of the Anxiety Related Experiences (ARX) Scale

Abstract

Post Traumatic Stress Disorder (PTSD) is heterogeneous in nature, which complicates diagnostic efforts and makes accurate assessment tools critical. The MMPI family of instruments are widely used broadband measures of psychopathology, including trauma symptomology. The MMPI–3’s Anxiety Related Experiences scale (ARX) is an expansion of the MMPI–2–RF Anxiety (AXY) scale which has historically represented the MMPI family’s best measure of trauma symptoms. This study expands research on ARX in 2 samples of college students (n = 332 [PCL–5 Criterion] & n = 58 [CAPS–5 Criterion]) by examining ARX’s incremental, criterion, and classification validity. ARX incrementally predicted PCL–5 total and cluster scores beyond that accounted for by AXY (R²Δ = .01–.09). ARX accounted for the most unique variance, beyond RCd and RC7, in CAPS-5 interview ratings of intrusion symptoms (R²Δ = .16). ARX was strongly related to trauma symptomology broadly (r = .42–.58) and demonstrated strong screening ability at T65 (sensitivity = .37–.40; specificity = .91–.92) and stronger diagnostic screening at T75 (sensitivity = .31; specificity = .93). We discuss clinical considerations when using ARX for assessing PTSD.

Disclosure statement

Paul Ingram receives research support from the University of Minnesota Press, publisher of the MMPI–family of instruments.

Data availability statement

Raw data were generated at Texas Tech University. Derived data supporting the findings of this study are available from the corresponding author [M. A. Keen] on request.

Notes

1 While all invited participants in Sample 2 scored ≥ 33 on the PCL-5 at the beginning of the semester when filling out the screening measure, PCL-5 scores reported here are from time of testing, which may have been up to 4 months after completing screening materials. As such, participant distress and/or trauma symptoms may have naturally abated with time, accounting for lower average scores in Sample 2 than expected given screening procedures.

2 MMPI-3 scale scores alone were used to evaluate protocol validity given that 1) the updated normative sample makes these scale scores the most appropriate criteria on which to base sample exclusions given when these data were collected, 2) MMPI-2-RF scale scores were only included in one sub-set of analyses (i.e., hierarchical regressions), and 3) Sample 2 only administered the MMPI-3 so MMPI-2-RF validity scale scores were unavailable. Cross-tabulations comparing protocol validity classifications across both versions of the MMPI in Sample 1 suggested that they agreed on the protocol validity of 364 out 404 cases (90%).

3 For additional information about the underlying nature of these statistics and ROC analyses used within this paper, readers are referred to Pintea & Moldovan (2009).