An estimated 7% of people with serious or persistent mental illnesses are put in jail or prison each year.

When mental illness develops in a family member or close friend, having to deal with the police and the courts may be the last thing you would expect. But people with mental illness are very vulnerable to arrest. When they are in a delusional or psychotic state, they may exhibit "nuisance" behavior or commit a crime that brings the police to the scene. People with mental illness also have an increased risk for substance abuse and homelessness, and these factors can also make them more visible to law enforcement officers.

It can be shocking to discover a loved one with mental illness is entangled in the criminal justice system, and very difficult to help get them on a path to treatment instead of incarceration. Faced with this personal tragedy, families may not appreciate that their problems are part of a broad, nationwide trend that has been escalating for several decades.

The Miami-Dade County jail Florida holds five times as many people with mental illness than any psychiatric hospital in the state.

When people with mental illness are discharged from prison, they often have trouble reconnecting with treatment providers and struggle to follow the conditions for community supervision that were required for their release. Some prisons discharge mentally ill prisoners with only a two-week supply of medication when it can take weeks to get an appointment at a community health center to continue their prescription.

Because of their period of incarceration, a person with mental illness may also have lost their job or access to essential benefit programs that had sustained them, increasing the likelihood of problems like homelessness. This often leads to a cycle of repeated arrest and incarceration that is costly to society, increasingly debilitates the person with mental illness, and is painful for families trying to provide ongoing, and much needed, support.

Once in prison or jail, people with mental illness often have difficulty obtaining their medication or other treatment. Their condition, which might be degrading due to the lack of treatment and the stress of the situation, can make it impossible for them to comply with the rigid rules in the regulated, restrictive environment of a prison. As an institution, a jail is rigidly structured to maintain safety, and prisoners with mental illness often break the rules leading to additional punishments and consequences. As the symptoms of their illness progress, their unusual behavior may make them a target for other inmates. All these factors combine to put prisoners with mental illness at a high risk for suicide while incarcerated. What begins as an arrest for petty theft, trespassing, public urination, or other minor infraction can turn into a prolonged period of incarceration, much longer than the brief sentence that would routinely be imposed on someone without a mental illness.

16% of the population in prison has a mental illness, compared to 5% of the U.S. population.

The cost of repeatedly arresting people with mental illness is staggering. A study of Summit County, Ohio found that in the course of one year the government spent more than $1 million on just 20 people, who were repeatedly arrested, committed to hospitals for 72 hours, jailed, or put in detoxification facilities. In Pennsylvania, a study found that inmates with mental illness cost nearly twice as much per day compared with other inmates in the prison population.