Cognitive underperformance and symptom over-reporting in patients with acquired brain injury and neuropsychiatric problems
Summary
Neuropsychological assessment in patients with Acquired Brain Injury (ABI) can be influenced by cognitive underperformance (lower performance due to lower effort) or by symptom over-reporting (patients reporting more symptoms than they actually have). This study aimed to examine factors related to cognitive underperformance and symptom over-reporting and to investigate their influence on cognitive measures in patients with ABI and neuropsychiatric problems. Patients (N=170) were recruited from two mental health centres in the Netherlands. The Amsterdam Short Term Memory Test (ASTM), the Test of Memory Malingering and the Structured Inventory Malingered Symptomatology (SIMS) were used to measure symptom validity. Patients who failed these tests were compared to patients who passed the test on age, gender, educational level, depression, awareness, executive function, and memory. The cognitive underperformers were significantly older than the control group (p = .021). The symptom over-reporting group reported significantly more depressive symptoms (p = .009) and their Awareness Questionnaire (AQ)-discrepancy scores were significantly lower (p = .05) than the control group. No association was found of cognitive underperformance with the cognitive measures. Symptom over-reporting was associated with lower memory scores (β = .30, p = .010). In conclusion, age appeared to be the strongest predictor of cognitive underperformance. Depression and an underestimation of functioning seem to predict symptom over-reporting. The use of the ASTM in this patient group should be further investigated, however the SIMS may be a good indicator of lower effort in memory tests.