ADHD tied to driver's license delays, crash risks

(Reuters Health) - Adolescents with attention deficit hyperactivity disorder (ADHD) may wait longer than other teens to obtain a driver’s license, and they may be at higher risk for accidents once they do start driving, suggests a new study.

Overall, however, the increased risk of a motor vehicle accident among people with ADHD is not as high as was reported in previous studies, the researchers found.

“It’s commonly reported that new drivers with ADHD have a four-fold increased risk of getting into crashes than the general population of young drivers,” senior author Thomas Power, of the Children’s Hospital of Philadelphia, told Reuters Health. “But some have suggested the risk is lower.”

People with ADHD may be overactive and have problems with attention and impulsivity, according to the U.S. Centers for Disease Control and Prevention. Recent surveys suggest more than one in 10 U.S. children and teens have been diagnosed with ADHD.

For the new study, researchers analyzed medical records of 18,344 young residents of New Jersey born between 1987 and 1997, including 2,479 with ADHD. Their medical records were linked with data spanning 2004 through 2014 on licensing and motor vehicle crashes in New Jersey.

Compared to young people without ADHD, those with ADHD were 35 percent less likely to obtain a driver’s license within six months of becoming eligible for it. This was true for both boys and girls.

The researchers can’t say why getting a driver’s license took longer for young people with ADHD, Power said. Parents may have delayed the driving tests or students may have taken longer to pass the exams.

The researchers also found that young people with ADHD were 1.36 times more likely to be involved in a motor vehicle accident during the study period than those without the condition.

About 43 percent of young people with ADHD were in a crash, compared to about 36 percent of those without ADHD. The increased crash risk among young drivers with ADHD did not vary by gender or by age when they passed the driving test.

There was no extra crash risk for people taking ADHD medications, but Power said the number of participants on treatment was too small to allow for a difference to show up.

The study, Power said, “broadly indicates that we need to be concerned about adolescents with ADHD getting a driver’s license and we need to provide careful screening, assessment, consultation and coaching.”

But given that the increased risk of crashes was nowhere near the four-fold higher odds reported elsewhere, “We don’t want to be overly concerned and afraid to proceed as a general rule,” he said.

Zheng Chang, of the Karolinska Institute in Stockholm, whose research team recently reported on the benefits of treating ADHD in adult drivers, said parents of teens with ADHD should understand the increased risk of accidents and the benefits of medication.

“It is important for parents and teens to keep in mind that ADHD may persist into adolescence and adulthood,” with an associated risk of motor vehicle crashes, Chang told Reuters Health in an email.

More research is needed to find out whether ADHD treatment improves long-term crash risks and other outcomes, said Chang, who was not involved with the new study.

SOURCE: JAMA Pediatrics, online June 12, 2017.