Forensic considerations of substance-induced psychosis.

In forensic psychiatry, one is often called on to examine an accused to determine if he has a mental disorder, thus opening a defense to criminal charges. To this end, the psychiatrist must consider, in the final analysis, whether the accused could meet the test for the insanity defense, taking into account the definitions of legal insanity extant in the jurisdiction. In some jurisdictions, mitigating factors such as intoxication or diminished capacity may lead to reduced convictions. Substance-induced psychosis could represent a more complex clinical scenario. Often, it is not possible to distinguish substance-induced psychosis from a first-episode psychosis in the context of a primary mental disorder due to the very high level of comorbidity. A recent Supreme Court of Canada judgment (R. v. Bouchard-Lebrun) held that substance-induced psychosis cannot be considered a disease of the mind in the legal sense when it results from self-induced intoxication. In this editorial, I will review some notions of substance use and psychosis, particularly in the legal context, and evoke some discussion about differences in perception between tribunals of law and the medical or scientific community. This topic will be discussed in the Canadian context principally, but some of the ideas should be of interest to the general forensic psychiatry community. Psychosis and Violence