Past research efforts have found that drivers with attention-deficit/hyperactivity disorder (ADHD) are at a greater risk of getting in a vehicle crash. But a newly released 10-year study concludes that such drivers can significantly lower that risk by taking prescribed medication for the condition.

Symptoms of ADHD include inattention, impulsiveness, and a proclivity for risk taking and aggressive action — traits that can raise the risk of getting in a collision. The study concluded that male ADHD patients had a 38% lower risk of a crash while taking prescribed medication, compared to months when they were off their medication. Women with ADHD had a 42% lower crash risk while receiving ADHD medication.

Researchers estimated that up to 22.1% of motor vehicle crashes involving people with ADHD could have been avoided if the drivers were on medication.

The study examined the health insurance claims of more than 2.3 million Americans diagnosed with ADHD. The claims, made from the beginning of 2005 to the end of 2014, revealed when patients received medication for ADHD and also when they were treated for injuries suffered in a traffic accident. The average age of these patients was 32.5 years old, and 51.7% were female.

Zheng Chang, a postdoctoral researcher with Karolinska Institute in Stockholm, Sweden, authored the study. It was published in JAMA Psychiatry.