Many ADHD (attention-deficit hyperactivity disorder) sufferers are less likely to commit a crime while on appropriate medication, a Swedish study found.
The study, by researchers at the Karolinska Institute in Stockholm, found that while people with ADHD were far more likely to break the law, the use of Ritalin, Adderall and other drugs to curb hyperactivity and boost attention markedly reduced rates of reoffending, the Associated Press reported.
The researchers focused on older teens and adults with ADHD, studying a Swedish registry of more than 25,650 people with ADHD and comparing their medication history with criminal records from 2006 to 2009, WebMD reported.
The number of crimes committed was about a third or more lower in those taking medication, the study found.
Lead author Paul Lichtenstein said in a statement quoted by Reuters:
"It's said that roughly 30 to 40 percent of long-serving criminals have ADHD. If their chances of recidivism can be reduced by 30 percent, it would clearly affect total crime numbers in many societies."
Support groups and preventative medicine experts seized on the study results, saying better access to medication could reduce crime.
They also said it demonstrated the efficacy of medications in older patients.
About 5 percent of children in the US and other Western countries reportedly have ADHD, characterized by impulsiveness, hyperactivity and difficulty paying attention.
While children are routinely given medication to help them focus in school, many sufferers retain symptoms into adulthood.
The AP quoted Dr. William Cooper, a pediatrics and preventive medicine professor at Vanderbilt University in Nashville, as saying:
"There definitely is a perception that it's a disease of childhood and you outgrow your need for medicines. We're beginning to understand that ADHD is a condition for many people that really lasts throughout their life."
The findings were published in Thursday's New England Journal of Medicine.