STOCKHOLM, Sweden, Nov. 28 (UPI) -- Criminal behavior in people with attention-deficit hyperactivity disorder drops when the people are on medication, Swedish researchers say.
Henrik Larsson of Karolinska Institutet, in Stockholm, said previous research showed people with ADHD were more likely to enter a life of crime, but it was uncertain how ADHD medication impacted.
Larsson and colleagues studied more than 25,000 individuals with ADHD from different registries over a four-year period.
The study, published in the New England Journal of Medicine, found the incidence of criminal behavior was lower amongst medicated individuals than unmedicated ones.
"We have shown that ADHD medication very probably reduces the risk of crime," Larsson said in a statement. "However, we need to point out that most medical treatments can have adverse side effects, so risks must be weighed up against benefits and the individual patient's entire life situation taken into consideration before medications are prescribed."
Co-author Professor Paul Lichtenstein of the same department said the potential pros and cons of each prescription have to be evaluated.
"What we're saying is that this probable reduction in the risk of crime must also be taken into account. It's said that roughly 30 percent to 40 percent of long-serving criminals have ADHD," Lichtenstein said. "If their chances of recidivism can be reduced by 30 percent, it would clearly effect total crime numbers in many societies."