appreciation test
appreciation test. Criminal law. A test for the insanity defense requiring proof by clear and convincing evidence that at the time of the crime, the defendant suffered from a severe mental disease or defect preventing him or her from appreciating the wrongfulness of the conduct. • This test, along with the accompanying plea of not guilty by reason of insanity, was established by the Insanity Defense Reform Act of 1984. 18 USCA § 17. — Also termed Insanity Defense Reform Act of 1984 test. See INSANITY DEFENSE. [Cases: Criminal Law 48.]