The rationale behind symptom over-reporting tests is that patients with no intention to feign symptoms will perform below a specific cut-off point because of the bizarreness of the symptoms presented. Given this rationale, very few studies have attempted to determine the specificity of these measures, i.e., whether clinical psychiatric patients would not endorse these exaggerated symptoms. In the present studies, endorsement of bizarre and atypical symptoms in such patients was explored. In two studies, the Structured Inventory of Malingered Symptomatology (SIMS) was administered to a sample of schizophrenia patients (study 1 n = 18; study 2: n = 23) and healthy controls (study 1 n = 19; study 2 n = 24) together with a neurocognitive test (Wisconsin Card Sorting Test; study 1) and schizophrenia symptomatology indices (study 2; PANSS and PSYRATS). Results from both studies indicate that serious psychopathology may significantly interfere with symptom validity performance measures: According to the SIMS cut-off criteria, symptom over-reporting would be present in almost 30 percent of the schizophrenia patients (28% in study 1 and 30% in study 2) but not in the healthy sample. Furthermore, SIMS scores in the schizophrenia sample explained a significant amount of variance in neurocognitive performance (study 1) and was positively correlated with PANSS positive symptomatology (study 2; r = .58, p <.01), PANSS distress (study 2; r = .50, p <.05), and PSYRATS hallucination and total scores (r = .60, p <.01 and r = .75 p <.001). Consequently, it is discussed that cut-off points may need adjustment in psychotic patients with positive symptomatology when litigation is clearly not an issue.
- neurocognitive dysfunction
- symptom validity