The importance of illness behavior in disability management.

Abnormal illness behaviors, ranging from non-deliberate distortion to intentional deception, are associated with clinical phenomena that lie along a continuum from unconscious symptom exaggeration to psychiatric disorders and malingering. Failure to recognize abnormal illness behavior leads to inappropriate treatment and erroneous estimates of impairment or disability. This review is divided into three sections. First, basic terms are defined, including dissimulation, distortion, deception, misattribution, false imputation, and malingering. Second, syndromes characterized by abnormal illness behavior are described, including somatization, somatoform disorders, factitious disorders, and symptom magnification. Third, methods for detecting deception are illustrated, including maximum voluntary effort assessment, objective personality inventories, and symptom validity testing.