Malingering Assessment: Evaluation of Validity of Performance

Consideration of symptom exaggeration or overt malingering is of particular importance in assessment of alleged mild head trauma and other mild or questionable personal injury situations. Validity is the extent to which tests assess what they were designed to measure. The determination of invalidity is part of the overall neuropsychological interpretation process. In neuropsychology a line of validity assessment research has developed, leading to three general approaches to validity and/or malingering assessment: (a) symptom validity measures, (b) invalid patterns of performance on clinical neuropsychological measures, and (c) concomitant extra-test behavioral information or observations. In each case some aspect of behavior is compared to an external standard or to other intra-subject behavior. Inconsistencies and discrepant comparisons are cause for validity concerns. These approaches are described and recommendations are provided based on the extant literature. However, validity assessment is difficult and at times ambiguous in part because real and feigned deficits are not mutually exclusive. In some clinical situations the most that can be said about an invalid performance is that it is not indicative of the true neurobehavioral capabilities of the person being evaluated, and is not consistent with the presumed etiologic event.