Detection of feigned head injury symptoms on the MMPI-2 in head injured patients and community controls.

MMPI-2 results from 39 moderately to severely head injured (HI) and 44 community volunteer (CV) participants given instructions to feign symptoms or answer honestly during an analog forensic neuropsychological examination were compared. No significant effects for HI or the interaction between the HI and instruction set (IS) factors were noted on either clinical or selected validity scales (F, Fb, Fp, Ds2, FBS). However, the main effect of IS was significant for both clinical and validity scales (median Cohen's d=1.34 and 1.39, respectively). Most validity scales were characterized by perfect specificity rates but low to modest sensitivity, whereas FBS had both moderate sensitivity and specificity. Logistic regressions showed that the F and Ds2 scales made a significant contribution independent of motivational tests to the identification of feigning during neuropsychological examination.

Head injury and the ability to feign neuropsychological deficits.

This study investigated the possibility that head-injured patients, by virtue of their exposure to medical and legal evaluations, are better able to feign deficits than controls. Both internal and external validity issues were addressed in a malingering simulation using 46 moderately to severely head injured and 46 matched control subjects who were administered a battery of neuropsychological and motivational tests under standard or malingering instructions. Results showed no significant interaction between malingering instructions and head injury status on commonly used motivational tests or neuropsychological tests, nor were the head injured malingerers better able to avoid detection using established cutting scores on motivational tests. These results suggest that head injured individuals are no more able to feign neuropsychological deficits successfully than non-head injured individuals.