Voluntary Intoxication and the Insanity Defense

Abstract

Voluntary intoxication can be used as a basis for the insanity defense in certain cases. I review the obscure concept of “settled insanity “ in California case law and note its 100–year evolution from a “permanent” state of mind, usually associated with chronic alcoholism, to a current test of temporary insanity wherein the mental disorder must be fixed, stable, of reasonable duration, and not solely dependent upon the ingestion or duration of the drug. I argue that this definition is tautological and arbitrary and propose a new definition of “settled insanity” based only upon a demonstrated predisposition to psychosis. This definition is consistent with current scientific research concerning psychosis-proneness in individuals who become paranoid and delusional through the use of psychostimulants, the class of drugs now most likely to contribute to a voluntary intoxication-insanity defense strategy.