A new index for the MMPI 2 Test for detecting dissimulation in forensic evaluations: A pilot study

This pilot study is the starting point of a potentially broad research project aimed at identifying new strategies for assessing malingering during forensic evaluations. Participants: The forensic group was comprised of 67 males who were seeking some sort of certification (e.g. adoption, child custody, driver’s license, issuance of gun permits, etc.); the non-forensic group was comprised of 62 healthy male volunteers. Method: Each participant was administered the MMPI-2. Statistical analyses were conducted on obtained scores of 48 MMPI-2 scales. In the first step, parametric statistics were adopted to identify the best combination of MMPI-2 scales that differentiated the two groups of participants. In the second step, frequency-based, non-parametric methods were used for diagnos tic purposes. Results: a model that utilized the best three predictors (“7-Pt”, “L”, and “1-Hs”) was developed and used to calculate the ForensicEvaluation Dissimulation Index (FEDI), which features satisfactory diagnostic accuracy (0.9), sensitivity (0.82), specificity (0.81), and likelihood ratio indices (LR+=4.32; LR-=0.22).