Licensing and motor vehicle crash risk among teens with ADHD

The defining symptoms of ADHD (inattention, hyperactivity and impulsivity) have been linked to unsafe driving behaviors.

Allison E. Curry, Ph.D., M.P.H., of the Children's Hospital of Philadelphia (CHOP), and coauthors linked electronic health records to New Jersey traffic safety databases for more than 18,000 primary care patients of the CHOP health care network born from 1987 to 1997. Study analyses were restricted to 2,479 adolescents and young adults with ADHD and 15,865 without ADHD who had at least one full month of follow-up after becoming age-eligible for licensure, which in New Jersey is at the minimum age of 17.

Compared with individuals without ADHD, the probability that individuals with ADHD would be licensed six months after eligibility was 35 percent lower. Newly licensed drivers with ADHD also had a 36 percent higher first crash risk than those without ADHD. Among those individuals with a driver's license, 764 of 1,785 with ADHD (42.8 percent) and 4,715 of 13,221 without ADHD (35.7 percent) crashed during the study period. Few individuals with ADHD (12.1 percent) had been prescribed medication in the 30 days before they were licensed to drive, according to the results.

Limitations of the study include that the prevalence of ADHD in the study group was somewhat higher than U.S. estimates and the results may have limited generalizability because New Jersey has an older licensing age at 17 and it is highly urbanized.

"Future research is needed to examine parent and clinician management of licensure decisions and crash risk among patients with ADHD, elucidate sex-specific mechanisms by which ADHD influences crash risk to develop countermeasures, and examine real-world effectiveness of medication use and detrimental effects of distractions," the article concludes.