An extensive study of almost 48,000 ex-prisoners in Sweden has drawn attention to the link between common psychiatric disorders and the likelihood of reoffending with a violent crime after release. The study published in The Lancet Psychiatry journal included alcohol and drug abuse as a psychiatric disorder.
Professor of Forensic Psychiatry and lead author Susan Fazel stated that one out of every seven prisoners has a psychotic illness or major depression. In addition, around one in five of the prisoners have a clinically significant substance abuse disorder when they enter prison.
A team of British and Swedish researchers examined common psychiatric disorders and any violent convictions in all prisoners released in Sweden between January 1, 2000 and December 31, 2009. The researchers also compared the rate of violent reoffending with that of sibling prisoners with and without a psychiatric disorder. Using this data, the team then estimated the proportion of violent reoffenses that could be attributed to psychiatric disorders.
About 60% of the female prisoners had a psychiatric disorder, and 11% were convicted of a violent crime after their release. Male prisoners had a lower rate of psychiatric disorders with 42% having such a condition. One quarter of these individuals were convicted of a violent crime following their release.
The researchers found a strong link between the presence of a psychiatric disorder and the likelihood of perpetrating a violent crime after release. Male prisoners with a psychiatric disorder were 63% more likely to commit a violent crime after release than other prisoners, while females with a psychiatric disorder were twice as likely to do so.
The team took other factors such as age, employment, marital status, immigrant background, and criminological factors in account. Even after this, the strong link remained.
While all psychiatric diagnoses were associated with an increased rate of violent offenses after release, the researchers found higher rates for prisoners with certain psychiatric conditions. These diagnoses included alcohol and drug abuse, ADHD, personality disorder, bipolar disorder, and schizophrenia among others.
Fazel stated that their research “underscores the importance of treating alcohol and drug misuse activity actively.” The authors of this research paper argue that national violence prevention strategies should include prison health in their strategies, targets, and surveillance.
While many people are highly concerned about the link between mental illness and crime, this research indicates that drug and alcohol abuse are also significant factors leading to violent crime.