Attention-deficit hyperactivity disorder (ADHD) is one of the most common psychiatric problems these days, and it’s not just a kid thing. As children with the disorder age, they don’t always grow out of it, so many adults live with ADHD as well. The National Institute of Mental Health (NIMH) estimates that over 8% of the population in the US will be affected by ADHD over the course of their lifetimes.

People with ADHD often act before they think, and adults with ADHD are more likely to commit crimes. For this reason it may be wise to continue to medicate adults who have not outgrown the impetuous and volatile behavior patterns often associated with ADHD. A new study looked at whether being on ADHD medications, versus leaving one’s ADHD untreated, might reduce a person's risk for criminal behavior.

Over all, the reduction in criminal behavior while on ADHD meds was almost a third for women, and for men, it was even greater, at 41%.

Researchers followed over 25,000 people in Sweden who had been given an ADHD diagnosis. They tracked the instances of criminal behavior over three years in people who were on and off medication for the disorder. People on medication were less likely to carry out criminal behaviors than those who did not take medication. Even within an individual, periods when he or she was on medication for ADHD were linked to significantly reduced risk for criminal behavior compared to a person’s unmedicated periods. Over all, the reduction in criminal behavior while on ADHD meds was almost a third for women, and for men, it was even greater, at 41%.

"We have shown that ADHD medication very probably reduces the risk of crime," said study author Henrik Larsson in a news release. "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."

This study doesn't prove that one variable causes the other – that ADHD “causes” criminal behaviors or that medications stop them. But the data do suggest a nice Correlational study between these factors, and doctors might want to take the study into consideration when deciding whether to try medication for a person with ADHD. For young people with ADHD who are at higher risk of committing crimes, it may be particularly important to think about how medication may affect their risk. But as always, weighing the pros and cons of a medication is crucial – and highly personal. So talk with your doctor if you are thinking about going on or off a medication, and be willing to revisit the decision if problems arise.

The study was carried out by researchers at the Karolinska Institutet in Sweden, and published in the The New England Journal of Medicine.