Psychological variables and Wechsler Adult Intelligence Scale-IV performance

Abstract

The MMPI-2 and WAIS-IV are commonly used together in neuropsychological evaluations yet little is known about their interrelationships. This study explored the potential influence of psychological factors on WAIS-IV performance in a sample of 180 predominantly male veteran referrals that underwent a comprehensive neuropsychological examination in a VA Medical Center. Exclusionary criteria included failed performance validity testing and self-report distortion on the MMPI-2. A Principal Components Analysis was performed on the 15 MMPI-2 content scales, yielding three broader higher-order psychological dimensions: Internalized Emotional Dysfunction (IED), Externalized Emotional Dysfunction (EED), and Fear. Level of IED was not related to performance on the WAIS-IV Full Scale IQ or its four indexes: (Verbal Comprehension, Perceptual Reasoning, Working Memory, and Processing Speed). EED was not related to WAIS-IV performance. Level of Fear, which encompasses health preoccupations (HEA) and distorted perceptions (BIZ), was significantly related to WAIS-IV Full Scale IQ and Verbal Comprehension. These results challenge the common use of high scores on the MMPI-2 IED measures (chiefly depression and anxiety) to explain deficient WAIS-IV performance. In addition, they provide impetus for further investigation of the relation between verbal intelligence and Fear.

Keywords: Intelligence testing; MMPI-2; Wechsler Adult Intelligence Scale; neuropsychological assessment; psychopathology.