Mental Disorders

Questions regarding a criminal defendant's possible mental disorder may emerge during nearly any point in criminal justice proceedings: arrest, preliminary hearings, trial, sentencing, incarceration, and release. Oftentimes, the law explicitly identifies the relevance of mental disorder. In the United States, for example, legal doctrine addresses the ways in which mental disorder might affect a criminal defendant so severely that it precludes participating in trial or precludes culpability for a given offense. On the other hand, there is no comprehensive or integrated approach to mental disorder within the criminal justice process. Mental disorder may prove relevant to one legal question but not to another, and different disorders—even different symptoms of the same disorder—may result in substantially different legal outcomes.

The attention the law gives to mental disorder is understandable when one considers the prevalence of mental illness among those who pass through the criminal justice system. For example, Richard Redding cites U.S. Justice Department statistics indicating that 35 percent of jail and prison inmates suffer from a mental disorder, and a recent large-scale study of pretrial arrestees in New York found that 22 percent had a moderately serious or serious mental illness. Nor is mental disorder relevant only to questions of criminal law. Aspects of civil law address mental disorder when it causes concern that an individual may pose a danger to self or others, even if the individual violates no criminal law. Other psycholegal questions in the civil context require determining, for example, whether mental disorder so impairs an individual that the individual cannot competently consent to medical treatment or execute a will.