The Effect of Failure on Cognitive and Psychological Symptom Validity Tests in Litigants with Symptoms of Post-traumatic Stress Disorder

• Published in: Clinical neuropsychologist 2008-09, Vol.22 (5), p.879-895
• Main Authors: Demakis, George J., Gervais, Roger O., Rohling, Martin L.
• Format: Article
• Language: English
• Subjects: Adult; Adult and adolescent clinical studies; Anxiety disorders. Neuroses; Biological and medical sciences; Cognition - physiology; Emotions - physiology; Female; Humans; Intelligence Tests - statistics & numerical data; Male; Medical sciences; Memory - physiology; Middle Aged; Neuropsychological Tests - statistics & numerical data; Personality Tests - statistics & numerical data; Post-traumatic stress disorder; Psychiatric Status Rating Scales - statistics & numerical data; Psychological Tests - statistics & numerical data; Psychology. Psychoanalysis. Psychiatry; Psychometrics - methods; Psychometrics - statistics & numerical data; Psychopathology. Psychiatry; Reproducibility of Results; Severity of Illness Index; Stress Disorders, Post-Traumatic - diagnosis; Stress Disorders, Post-Traumatic - physiopathology; Stress Disorders, Post-Traumatic - psychology; Verbal Learning - physiology
• ISSN: 1385-4046; 1744-4144
• DOI: 10.1080/13854040701564482

This study examined the influence of performance on cognitive and psychological symptom validity tests on neuropsychological and psychological test performance in claimants evaluated in a medico-legal context (N  = 301) with symptoms of PTSD. A second purpose of this study was to examine the influence of the severity of PTSD symptoms on cognitive test performance after excluding patients who failed to put forth adequate best effort and who exaggerated psychiatric symptoms. Patients were administered a battery of neuropsychological measures that were aggregated into a composite measure, the Cognitive-Test Battery Mean (C-TBM). Patients were also administered a battery of psychological tests that were aggregated into another composite measure, the Psychological-Test Battery Mean (P-TBM). We found that failure on cognitive symptom validity tests was associated with significantly poorer neuropsychological functioning, but there was not a significant effect on psychological symptoms. Conversely, failure on psychological symptom validity tests was associated with higher levels of psychopathology, but there was not a significant effect on cognitive ability. Finally, once patients were screened for adequate effort and genuine symptom reporting, the severity of PTSD symptoms did not appear to influence cognitive ability. This is the first study that assessed both types of symptom validity testing in PTSD claimants, which is important given that previous literature has demonstrated cognitive impairment in PTSD and that individuals with PTSD tend to claim cognitive impairment. Implications of these findings are discussed with regard to the existing literature and the relationship between these two types of symptom validity tests.