In Reply: Of the handful of controversies in mental health, the "criminalization" of mental illness may be unique in that practically everyone with an opinion is to some extent right. As someone once said about the answer to any important question, "It depends …." In the case of criminalization, it depends mostly on the subgroup of patients being considered. Thus it is possible to have one's feet firmly planted in both camps by acknowledging an obvious association between delusions and crime in an acutely psychotic population (1), while simultaneously reporting little or no association between mental illness and crime in a presumably less acute population, as we did in the study reported in the June issue.
The disturbing fact to be explained is the overrepresentation of persons with mental illness in our jails and prisons. This fact raises obvious questions about whether (and how) persons with mental illness are handled differently by the criminal justice system, especially the police and courts. Research addressing these questions has produced equivocal results. However, we were able to state confidently that the individuals in our sample were not arrested simply for displaying symptoms of mental illness and that mental illness had no obvious effect on the vast majority of criminal offenses we investigated—again, with the caution that these individuals may have represented a less acute subgroup of patients.
If not differential handling by the police and courts, how is it that persons with mental illness are overrepresented in jails and prisons? As noted above, psychosis is associated with crime. However, the available evidence indicates that psychosis-driven crime is rare and therefore is unlikely to account for the disproportional incarceration rates. Draine and colleagues (2) offered an explanation for the apparent criminalization of mental illness based on the "social context" in which many persons with mental illness find themselves. This social context is characterized by more powerful risk factors for crime, such as unemployment, poverty, homelessness, and especially, substance abuse. Their argument is persuasive, and parts of it were picked up by Fichtner and Cavanaugh in their letter.
Fichtner and Cavanaugh argue that the decriminalization of cannabis would effectively eliminate one pathway to jail or prison for persons with mental illness. They also imply that resources formerly used to enforce the criminalization of cannabis could be reallocated to mental health and substance abuse treatment. By their reasoning, it seems a win-win proposition for persons with mental illness who abuse substances—less jail time, more treatment.
However, we are not convinced that the decriminalization of cannabis would be totally, or even mostly, benign. Recent evidence seems to confirm historical concerns that use of cannabis increases the risk of schizophrenia and depression (3). The demonstration of a dose-response effect for both illnesses (4) suggests that our attention should be focused on getting habitual users to decrease their use rather than encouraging more widespread use by decriminalization. The positive economics of the decriminalization of cannabis may have been worked out without consideration of new costs, economic and social, contributed by cannabis-induced mental illness. Until the extent of these new costs is determined, we simply cannot know whether we would be replacing one problem with another.
Junginger J, McGuire, L. Psychotic motivation and the paradox of current research on serious mental illness and rates of violence. Schizophrenia Bulletin 30:21-30, 2004
Draine J, Salzer M, Culhane D, et al: Role of social disadvantage in crime, joblessness, and homelessness among persons with serious mental illness. Psychiatric Services 53:565-573, 2002
Rey J, Tennant C: Cannabis and mental health. British Medical Journal 325:1183-1184, 2002
Van Os J, Bak M, Hanssen M, et al: Cannabis use and psychosis: a longitudinal population-based study. American Journal of Epidemiology 156:319-327, 2002