A cautionary note on the determination of malingering in offenders

Abstract

The detection of genuine or feigned presentations of mental disorder is an important task for the forensic clinician. An empirically devised measure to detect malingering, the Structured Interview of Reported Symptoms (SIRS; Rogers et al., 1992), has shown promise in classifying participants as feigning. The SIRS format is a structured interview situation with primary and supplementary scales which represent measures of strategies observed when individuals' feign symptoms of mental disorder. The present paper examines the extent to which SIRS data is influenced by a number of psychological variables inherent in closed social interview situations and the effects of these variables on probability estimates of feigning in a sample of prisoners referred to a medium secure unit. Results show that a number of the SIRS scales were significantly influenced by acquiescent responding, interrogative suggestibility and intelligence. Discriminant analysis demonstrated that acquiescent responding and the tendency to yield to questions presented verbally significantly predicted probability of classification as malingering on the basis of stringent criteria using both SIRS data and MMPI-2 validity indices. A high rate of false positives (79%) were identified in the malingering group. The relevance of the findings are discussed in relation to the use of the SIRS and the assessment of feigned presentations of mental disorder.

Key Words:

• malingering
• misclassification
• acquiescence
• interrogative suggestibility.