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, F(p), 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.