Mens Rea and Methamphetamine: High Time for a Modern Doctrine Acknowledging the Neuroscience of Addiction

By Meredith Cusick

Abstract

In American criminal law, actus non facit reum, nisi mens sit rea, “an act does not make one guilty, without a guilty mind.” Both actus reus and mens rea are required to justify criminal liability. The Model Penal Code’s (MPC) section on culpability has been especially influential on mens rea analysis. An issue of increasing importance in this realm arises when an offensive act is committed while the actor is under the influence of drugs. Several legal doctrines address the effect of intoxication on mental state, including the MPC, limiting or eliminating its relevance to the mens rea analysis. Yet these doctrines do not differentiate between intoxication and addiction.

Neuroscience research reveals that drug addiction results in catastrophic damage to the brain resulting in cognitive and behavioral deficits. Methamphetamine addiction is of particular interest to criminal law because it causes extensive neural destruction and is associated with impulsive behavior, violent crime, and psychosis. Furthermore, research has revealed important distinctions between the effects of acute intoxication and addiction. These findings have implications for the broader doctrine of mens rea and, specifically, the intoxication doctrines. This Note argues for the adoption of an addiction doctrine that acknowledges the effect of addiction on mens rea that is distinct from doctrines of intoxication.