It is well documented that large numbers of persons with mental illness are in the U.S. criminal justice system. For example, one study identified that 14.5 percent of males and 31 percent of females in jails were diagnosed with a serious mental illness.1 Another study, a national study of jails and state prisons, found that 23.9 percent of jail inmates and 15.4 percent of state prison inmates displayed psychotic symptoms within one year prior to the study.2 To put these numbers into perspective, at any given time, there are approximately three times more persons with serious mental illness in jails and prisons than in psychiatric hospitals.3 These figures do not include persons with serious mental illness on probation or parole. It is estimated that 16 percent of probationers4 and between 5 and 10 percent of parolees have a serious mental illness.5
The reasons for the high rate of persons with serious mental illness in the criminal justice system, often referred to as the criminalization of mental illness, are complex. An early explanation for this included the deinstitutionalization of mental health services, a lack of community-based mental health services, and changes in involuntary civil commitment laws.6 Deinstitutionalization sought to reduce the state psychiatric hospital population and develop community-based services for those persons who previously would have been hospitalized. The reduction in state psychiatric hospital beds did occur. For example, in 1955, there were 559,000 beds, or 339 beds per 100,000 population, while in 2000, there were 59,403 beds, or 22 beds per 100,000 population.7
Unfortunately, the number and type of mental health services were never developed to address the needs of people with serious mental illness in the community. In addition, two court cases in the 1970s restricted the use of involuntary civil commitment. In O’Connor v. Donaldson,8 the U.S. Supreme Court ruled that the state cannot involuntarily confine a nondangerous person, while in Lessard v. Schmidt,9 a federal district court ruled that persons undergoing civil commitment had due process procedural rights similar to those in the criminal justice system because of the loss of liberty. Some believe the effect of these changes was that persons with mental illness were being arrested for behaviors for which they previously would have been civilly committed.10 It is argued that as a result of the loss of psychiatric hospital beds, the lack of community-based services, and restrictions on involuntary civil commitment, persons with mental illness were essentially transferred from one institution, state hospitals, to another, jails and prisons, an event often referred as transinstitutionalization.11
There is a lack of evidence supporting this explanation of the criminalization of mental illness.12 Adding more hospital beds is unlikely to decrease the number of persons with serious mental illness in jails and prisons.13 Also, while increasing the availability of mental health services is important to addressing the criminalization of mental illness, it alone is likely not sufficient.14 Instead, it is now argued a more comprehensive approach is needed that includes access to mental health services and that addresses criminogenic factors that often lead to arrest and recidivism, such as substance abuse, homelessness, lack of education, and others.15 Focusing only on mental health treatment or only on criminogenic factors is unlikely to decrease the number of persons with serious mental illness in the criminal justice system.