United States v. Lyons: toward a new conception of legal insanity.

In United States v. Lyons (1984), the U.S. Fifth Circuit Court altered its definition of legal insanity to conform with recent recommendations of the American Bar Association and the American Psychiatric Association. This paper briefly reviews the social and legal context of the Court's ruling. The author then discusses the insanity defense's rationale and suggests an interpretation of the Court's new definition that should guide psychiatric testimony.