The BDAE Complex Ideational Material—a Measure of Receptive Language or Performance Validity?

Abstract Scores on the Complex Ideational Material (CIM) were examined in reference to various performance validity tests (PVTs) in 106 adults clinically referred for neuropsychological assessment. The main diagnostic categories, reflecting a continuum between neurological and psychiatric disorders, were epilepsy, psychiatric disorders, postconcussive disorder, and psychogenic non-epileptic seizures. Cross-validation analyses suggest that in the absence of bona fide aphasia, a raw score ≤9 or T score ≤29 on the CIM is more likely to reflect non-credible presentation than impaired receptive language skills. However, these cutoffs may be associated with unacceptably high false positive rates in patients with longstanding, documented neurological deficits. Therefore, more conservative cutoffs (≤8/23) are recommended in such populations. Contrary to the widely accepted assumption that psychiatric disorders are unrelated to performance validity, results were consistent with the psychogenic interference hypothesis, suggesting that emotional distress increases the likelihood of PVT failures even in the absence of apparent external incentives to underperform on cognitive testing.
Source: Psychological Injury and Law - Category: Medical Law Source Type: research