[Insufficient cooperativeness in forensic neuropsychiatric assessment: prevalence estimates of negative response bias].

In the context of independent medical examinations, negative response bias in patients is a problem of primary importance, especially in cases where self-reported symptoms cannot be directly verified by the examiner. Estimates of the prevalence of uncooperativeness in neuropsychological evaluations demonstrated that invalid test profiles are to be expected in a sizable minority of examinees. However, no estimates have ever been published in German-speaking countries. Symptom validity was checked in 235 patients who reported cognitive symptoms after suffering an accident and who underwent forensic neuropsychiatric assessment. Patient classification was based on the results obtained with the Word Memory Test (WMT) or the Medical Symptom Validity Test (MSVT). When applying the recommended cutoffs for these tests, 44.3 percent of the sample was found to be classified as suspect for insufficient effort. In a subsample of 47 patients with claims of posttraumatic stress disorder 51.1 percent were found to score below the cutoffs. These findings underline the importance of modern methods for assessment of symptom validity in forensic contexts. Cooperativeness of compensation claimants cannot be assumed solely on the basis of clinical impression.