TUESDAY, Nov. 1, 2016 (HealthDay News) -- Released prisoners may be less likely to commit violent crimes if they're prescribed certain kinds of psychiatric medications, a new study suggests.

These medications can affect someone's mental state. They include antidepressants, antipsychotics, psychostimulants, drugs to treat addiction and antiepileptic drugs, the researchers said.

The study authors looked at information on more than 22,000 prisoners in Sweden. They were released between July 2005 and December 2010. The researchers had a median of nearly five years of follow-up information.

During that time, 18 percent of the prisoners committed violent crimes, the researchers said.

Three classes of drugs were linked to much lower rates of violent crimes. Antipsychotics were tied to a 42 percent reduction in violent crimes. For psychostimulants, the reduction was 38 percent. Drugs to treat addiction were linked to a 52 percent reduction, the researchers reported.

Antidepressants and antiepileptics didn't seem to have an effect on violent crime rates, the study found.

Psychological treatments targeting general criminal attitudes and substance abuse also helped lower the likelihood of violent crimes. But these findings weren't stronger than those for medications, the researchers said.

"These findings may have implications for risk management, because prison psychological programs need appropriate facilities, require sufficiently trained and supervised therapists, and are likely to be relatively expensive," wrote the team led by Dr. Seena Fazel, from the University of Oxford in England.

Providing these drugs after release from prison may be a cost-effective way to reduce crime, the study authors suggested. They said more study is needed.

"Because prisoners with psychiatric disorders benefit from both pharmacological and psychological treatments, research should investigate whether combining therapies improves outcomes," the study authors said.

Between 2005 through 2010, more than one-third of released prisoners in the United States and the United Kingdom were convicted of a new crime within two years, according to background information with the study.

The study was published in the Nov. 1 issue of the Journal of the American Medical Association.

More information

The U.S. National Institute of Justice has more on recidivism.