Psychological disorders, including depression, bipolar disorder and trauma-related disorders, are rampant among inmates, and mental illness itself is a risk factor for landing in jail.

“We’ve, frankly, criminalized the mentally ill, and used local jails as de facto mental health institutions,” said Alex Briscoe, the health director for Alameda County in northern California.

The statistics paint a stark picture, with mental illness affecting a greater percentage of jailed women than men:

• In state prisons, 73 percent of women and 55 of men have at least one mental health problem
• In federal prisons, 61 percent of women and 44 percent of men
• In local jails, 75 percent of women and 63 percent of men

The Affordable Care Act—and its expansion of Medicaid—is expected to connect previously uninsured ex-offenders with medical care and mental health treatment. But in the short term, jails and prisons remain the places where those with severe psychosis are housed: There are now three times more people with serious mental illness incarcerated in the United States than in hospitals, and the types of behavioral and mental health problems among inmates are becoming more severe.

Even psychiatric patients who are actively being treated often get tangled up in the criminal justice system: in 2012, researchers reported that 12 percent of adult psychiatric patients receiving treatment in the San Diego county health system had been incarcerated; in 2013, 28 percent of Connecticut residents being treated for schizophrenia and bipolar disorder had been arrested or detained.

In trying to explain the rise in mental illness in prisons and jails, public health officials and researchers point to the closure of state psychiatric hospitals in the late 1960s. The closures were meant to allow patients to return to their families and live independently. In the ensuing decades, though, men and women once housed in institutions found themselves arrested, often for minor offenses. In Ohio, among 132 patients discharged from the state hospital, 17 percent of them were arrested within six months.  By 2006, the Department of Justice reported that 1 in 6 inmates in state prisons and 1 in four in local jails were psychotic.

For many of those inmates, their path to incarceration started in childhoods marked by trauma and poverty. Impulse disorders that are common among adult male inmates typically begin to set in between the ages of 10 – 12. “These guys were difficult kids in their households and in school,” said Jason Schnittker, professor of sociology at the University of Pennsylvania. Their problems in childhood, said Schnittker are “compounded by the fact that their families don’t have the resources or time to treat [them], and they end up in schools where they can’t get adequate resources to manage their conditions.”

Inmates with mental health problems are much more likely to have experienced or witnessed traumatic events during adolescence: “They grow up in homes witnessing violence and sexual abuse, and caregivers going in and out of jail,” said Dana DeHart, an assistant dean for research support at the College of Social Work at DeSaussure College in Columbia, South Carolina. “Victimization leads to or exacerbates mental health problems like depression, anxiety and PTSD.”

As they grow up, their conditions worsen, DeHart explained, and these fragile men and women turn to drugs or alcohol to soothe their anxiety or numb their pain. To pay for their addictions, they often get involved in property crimes and prostitution, and then escalate to violent offenses.

But jail and prison are particularly bad places to be mentally ill. Men and women with behavioral disorders and mental illness end up in stressful prison environments—many are put in seclusion for long stretches of time—that further exacerbate their conditions, researchers say. Inmates with mental illness are much more likely to be injured in prison fights. The Department of Justice reported that 20 percent of inmates with mental illness were injured in jailhouse fights compared to 10 percent of inmates without mental illness. In local jails, inmates with mental illness are three times as likely to be injured.

When these inmates are released, they often return to lives of poverty and trauma. Inmates say their top priorities upon release are getting a job and keeping their families together. Schnittker added, “All those challenges are worse if you’re depressed .”