Men with ADHD had a 38% lower risk of motor vehicle crashes (MVCs) when receiving ADHD medication, compared with months off medication. Women had a 42% lower risk, according to the results of a U.S. study.

Estimates suggested that up to 22% of MVCs in patients with ADHD could have been avoided if they had received medication during the whole length of the study, reported Zheng Chang, PhD , of the Karolinska Institutet, Sweden, and his colleagues (JAMA Psychiatry. 2017 May 10. doi: 10.1001/jamapsychiatry.2017.0659 )

A national cohort of 2,319,450 patients with ADHD was identified from commercial health insurance claims over 10 years followed by ED visits for MVCs, and they were matched with controls. There was an equal distribution of men and women, and the average age was 32 years. Of those patients 84% received ADHD medication, and 0.5% overall went to the ED because of MVCs. Patients with ADHD had a significantly higher risk of an MVC than did their matched controls (odds ratio, 1.49).

“This study is the first, to date, to demonstrate a long-term association between receiving ADHD medication and decreased MVCs,” said Dr. Chang and his associates. If this result demonstrates a protective effect, it is possible that continuous ADHD medication use might lead to lower risk of other problems, such as substance abuse disorder, or provide long-term improvements in life functioning for people with ADHD.

This study was supported by grants from the Swedish Research Council and the National Institute of Mental Health, as well as grants to two of the researchers from the Swedish Research Council for Health, Working Life and Welfare, and the National Institute on Drug Abuse. Dr. Chang and the other researchers had no relevant financial disclosures, except for Henrik Larsson, PhD, who received some speaker’s fees and research grants from pharmaceutical companies outside this work.