Malingering of mild closed head injury sequelae with the neuropsychological symptom inventory : a study of the effect of prior knowledge
Clinical neuropsychologists who assess patients following mild closed head injury (CHI) are often asked to offer an opinion whether there is evidence of malingering. Factors that impact the ability of a person to intentionally portray impairment are quite important since mis-diagnosis of malingering can result in delayed treatment. In this study knowledge of the sequelae of mild CHI was provided to normal college students in an effort to change reporting of symptoms and influence the type of malingering strategy used when completing the Neuropsychological Symptom Inventory (NSI). Subjects were randomly assigned to either a prior knowledge malingering group (PK;N=57), no prior knowledge malingering group (NPK;N=58), or control group (CON;N=61). The results showed that PK subjects endorsed more general and attention/concentration symptoms than NPK or CON subjects. The results also showed PK subjects were as likely to be detected by the NSI lie scale as NPK subjects. Thus, the NSI lie scale demonstrated sensitivity to malingering despite subjects having brief instruction about mild CHI. Also, having prior knowledge did not result in significantly different strategies when completing the NSI. Instead, both malingering groups reportedly used exaggeration and attempted to be consistent as frequent strategies.