Factitious disorders and malingering in relation to functional neurologic disorders

Interest in malingering has grown in recent years, and is reflected in the exponential increase in academic publications since 1990. Although malingering is more commonly detected in medicolegal practice, it is not an all-or-nothing presentation and moreover can vary in the extent of presentation. As a nonmedical disorder, the challenge for clinical practice remains that malingering by definition is intentional and deliberate. As such, clinical skills alone are often insufficient to detect it and we describe psychometric tests such as symptom validity tests and relevant nonmedical investigations. Finally, we describe those areas of neurologic practice where symptom exaggeration and deception are more likely to occur, e.g., postconcussional syndrome, psychogenic nonepileptic seizures, motor weakness and movement disorders, and chronic pain. Factitious disorders are rare in clinical practice and their detection depends largely on the level of clinical suspicion supported by the systematic collection of relevant information from a variety of sources. In this chapter we challenge the accepted DSM-5 definition of factitious disorder and suggest that the traditional glossaries have neglected the extent to which a person's reported symptoms can be considered a product of intentional choice or selective psychopathology largely beyond the subject's voluntary control, or more likely, both. We present evidence to suggest that neurologists preferentially diagnose factitious presentations in healthcare workers as "hysterical," possibly to avoid the stigma of simulated illness.