Abstract
Neuropsychology malingering base rates have not been widely investigated in Australia. Estimates in North America vary with as many as 4 in 10 people evaluated for personal injury or compensation cases suspected of exaggerating symptoms. Data on Australian neuro-psychology symptom exaggeration base rates were estimated using a modified and expanded version of a survey previously designed for this purpose (Mittenberg, Patton, Canyock, & Condit, 2002). Figures were based on an estimated 1818 annual cases involved in personal injury (n = 542), disability (n = 109), criminal (n = 108), or medical (n = 1059) matters. Symptom exaggeration base rates associated with referral type and diagnoses were variable. Specifically, 17% of criminal, 13% of personal injury, 13% of disability or workers compensation, and 4% of medical or psychiatric cases were reported to involve symptom exaggeration or probable symptom exaggeration. The highest rates of symptom exaggeration included cases referred for mild head injury (23%), pain or somatoform disorders (15%), moderate to severe head injury (15%), and fibromyalgia or chronic fatigue (15%). Overall, Australian symptom exaggeration base rates reported in this study were lower compared with base rates previously reported in North America.