Symptom and performance validation in patients with subjective cognitive decline and mild cognitive impairment

Nonauthentic symptom claims (overreporting) and invalid test results (underperformance) can regularly be expected in a forensic context, but may also occur in clinical referrals. While the applicability of symptom and performance validity tests in samples of dementia patients is well studied, the same is not true for patients with subjective cognitive decline (SCD) and mild cognitive impairment (MCI). A sample of 54 memory-clinic outpatients with evidence of SCD or MCI was studied. We evaluated the rate of positive results in three validity measures. A total of 7.4% of the patients showed probable negative response bias in the Word Memory Test. The rate of positive results on the Structured Inventory of Malingered Symptomatology was 14.8% while only one participant (1.9%) scored positive on the Self-Report Symptom Inventory using the standard cutoff. The two questionnaires were moderately correlated at .67. In a combined analysis of all results, five of the patients (9.3%) were judged to show evidence of probable negative response bias (or probably feigned neurocognitive impairment). In the current study, a relatively small but nontrivial rate of probable response distortions was found in a memory-clinic sample. However, it remains a methodological challenge for this kind of research to reliably distinguish between false-positive and correct-positive classifications in clinical patient groups.