Distinguishing genuine from simulated dissociative identity disorder using the Morel Emotional Numbing Test.

Objective: Few studies have identified validity tests that are appropriate for use in individuals with dissociative identity disorder (DID). This study investigated whether the Morel Emotional Numbing Test (MENT) could distinguish between genuine and simulated DID.

Method: Thirty-five participants with DID diagnosed via a semistructured interview were compared to 88 participants taking an abnormal psychology course who were instructed to simulate DID. Group comparison analyses were conducted to examine differences in the MENT errors. Univariate logistic regression and receiver operating characteristic curve analyses examined how well the MENT errors discriminated between groups and identified a cutoff optimizing sensitivity while maintaining high specificity.

Results: Simulators had significantly more errors across all three MENT sets compared to genuine DID participants. The total number of MENT errors across sets most strongly and significantly predicted genuine versus simulated DID groups. Receiver operating characteristic curve analyses indicated that the MENT could discriminate between genuine and simulated DID with outstanding classification accuracy (area under the curve = .95). A cutoff of ≥ 10 total errors on the MENT yielded an optimal balance of sensitivity (.86) and specificity (.94). However, the previously defined cutoff of ≥ 8 total errors also demonstrated high sensitivity (.87) and specificity (.89).

Conclusions: Findings provide preliminary evidence for the MENT as a validity test for DID populations. Although the commonly used cutoff of ≥ 8 errors on the MENT demonstrated excellent psychometric properties, we recommend using a cutoff of ≥ 10 errors for individuals with DID to minimize the risk of false positives while maintaining strong sensitivity. (PsycInfo Database Record (c) 2024 APA, all rights reserved).