C-46Emotional and Personality (MMPI-2) Factors in WAIS-IV Performance

Objective: We examined the potential effects of psychological factors (MMPI-2) on WAIS-IV performance after controlling for incomplete effort and distorted symptom reporting. Methods: Consecutive neuropsychological referrals (veterans, N = 125) with diverse diagnoses were administered a comprehensive battery including the WAIS-IV and MMPI-2. Referrals were screened for incomplete effort (Medical Symptom Validity Test) and symptom exaggeration (F, Fb, Fp). Factor analysis (PCA/Varimax) of MMPI-2 content scales was performed. Scores on these factors were examined in relation to WAIS-IV index scores on Verbal Comprehension, Perceptual Reasoning, Working Memory, and Processing Speed. Potential effects of age and education were examined. Results: Factor analysis revealed three major MMPI-2 content scale factors that accounted for 71% of the total variance: Social Withdrawal/Depression, Acting Out/Anger, and Fears/Bizarre Ideation. Correlations revealed a robust relationship between Fear/Bizarre Ideation and Verbal Comprehension (r = −.33, p < .001), with marginal relations between Withdrawal/Depression and Working Memory (r = −.18), and Processing Speed (r = −.20, p < .05). Acting Out/Anger was marginally related to Working Memory (r = −.20, p < .05). Age and education were not mediating factors. Conclusions: The MMPI-2 content scales appear to represent three broader dimensions of behavior, all of which have a mild association with working memory performance on the WAIS-IV. Processing speed was marginally related to Withdrawal/Depression. The most robust finding was an inverse relation between verbal–intellectual performance and Fears/Bizarre Ideation. In general, these results are consistent with previous investigations that suggest that clinicians should be cautious in attributing lower WAIS scores to psychological factors reflected in the MMPI-2.