Mental illness protects some inmates from returning to jail

Past studies compared inmates with severe mental illnesses, like schizophrenia and severe affective disorders, with a general population of released inmates and found that those with mental illnesses had higher recidivism rates.

The study's principal investigator Amy B. Wilson, assistant professor of social work at Case Western Reserve, said the researchers took a novel approach to studying recidivism among released inmates from one of the country's largest jail systems (Philadelphia) and separated inmates into four categories: those with severe mental illnesses, those with a substance abuse problem, those with dual problems of mental illness and substance abuse, and those with neither problem.

When looking at individual groups, those with mental illnesses alone fared better—even compared against those with no mental or substance abuse issues.

The findings from the study, "Examining the impact of mental illness and substance use on recidivism in a county jail," were reported in the International Journal of Law and Psychiatry.

The researchers looked at recidivism rates for 20,112 inmates admitted to the Philadelphia jail system in 2003 and then tracked their return rates over the next four years. Using data from Philadelphia's behavioral health system on Medicaid records and from the Philadelphia Country's jail system on admission, release and demographic information, the researchers were able to categorize the individuals into the four groups and follow their readmissions.

Of those readmitted to jail, 32 percent took place in the first year, increased to 45 percent by year two, 54 percent by year three, and 60 percent by year four.

At the end of four years, 54 percent of those with severe mental illness returned to jail, while 66 percent of those with substance abuse problems did, 68 percent of those with co-occurring issues, and 60 percent of those with no diagnosis did.

Each year of the study, those with severe mental illnesses had lower return rates than those in the other three groups.

Wilson says further study is needed, but she speculates that the services offered to those with mental illness alone upon release are more readily available than social services for individuals with dual problems or substance abuse. But much is yet to be learned about how mental illness can protect the inmates from further recidivism, Wilson said.

"These findings point to a possible need for more integrated services for mental and substance abuse, and more attention being paid generally to the ways that substance abuse involvement among people with serious mental illness complicates these individuals involvement with the criminal justice system" Wilson explains.

Provided by Case Western Reserve University