Symptom validity testing in medically unexplained pain: a chronic regional pain syndrome type 1 case series.

This study examines validity findings in a particular behavioral pain disorder. We examined two types of validity scores in 73 participants with a primary diagnosis of the controversial Complex Regional Pain Syndrome Type I (CRPS-1). All participants were incentivized by a disability-seeking context. Failure rates on performance validity tests ranged from 23% (Test of Memory Malingering) to 50% (Reliable Digit Span). Positive findings on symptom validity tests (MMPI-2 or MMPI-2-RF) ranged from 15% to 50% of subsamples. At least 75% of the sample failed one performance validity indicator and over half showed at least one positive symptom validity score. This initial study suggests that CRPS-1 could serve as a good patient model for studying the role of simulation in pain-related disability.