Older teens and adults with attention deficit disorder are much less likely to commit a crime while on ADHD medication, a provocative study from Sweden found.
It also showed in dramatic fashion how much more prone people with ADHD are to break the law - four to seven times more likely than others.
The findings suggest that Ritalin, Adderall and other drugs that curb hyperactivity and boost attention remain important beyond the school-age years and that wider use of these medications in older patients might help curb crime.
"There definitely is a perception that it's a disease of childhood and you outgrow your need for medicines," said Dr. William Cooper, a pediatrics and preventive medicine professor at Vanderbilt University in Nashville. "We're beginning to understand that ADHD is a condition for many people that really lasts throughout their life."
He has researched ADHD but had no role in the new study, which was led by Paul Lichtenstein of the Karolinska Institute in Stockholm. The findings were published in Thursday's New England Journal of Medicine.
For comparison purposes, researchers matched each ADHD patient with 10 similar people without the disorder from the general population.
- About 37 percent of men with ADHD were convicted of at least one crime during that four-year period, compared with just 9 percent of men without ADHD. For women, the crime rates were 15 percent with ADHD and 2 percent without it.
- Use of ADHD medicines reduced the likelihood of committing a crime by 32 percent in men and 41 percent in women.
The crimes were mostly burglaries or thefts. About 4,000 of more than 23,000 crimes committed were violent. ADHD medication use reduced all types of crime, Lichtenstein said.
ADHD medicines may help people organize their lives better and reduce impulsive behavior. They also bring a patient into counseling and health care, said Philip Asherson, a professor at the Institute of Psychiatry at King's College London.
"It's not necessarily just the medication" that is reducing the likelihood of crime, he said.
Still, Asherson said the study should lead to wider use of the drugs: "It firmly establishes the link between ADHD and criminality and establishes that medication has an impact on that criminality."