Legal insanity: assessment of the inability to refrain.

Maryland's test for a finding of legal insanity (not criminally responsible [NCR]) allows a defendant to be found legally insane due to either a lack of appreciation of wrongfulness (cognitive impairment [CI]) or lack of ability to refrain from illegal behavior (volitional impairment [VI]). During a four-year period, 1,446 defendants underwent in-depth (post screening) evaluations for the NCR plea at Maryland state hospitals. Of the 416 defendants assessed as NCR by the hospitals' court-appointed evaluators, 44 (11%) were assessed as NCR due to VI alone. Diagnostically, the VI and CI groups were similar. Criminal charges were also similar, but the VI group was more likely to have been charged with murder. Many of the forensic evaluators concluded that the VI group was unable to refrain from illegal conduct based on considering a number of factors, including psychiatric symptoms and the defendant's behavior as related to the offense. Some evaluators' reports offered an opinion, but did not adequately explain what data they used to arrive at their conclusion. This paper examines the history of and rationale for a volitional test of insanity and how it is assessed by forensic evaluators.