When Teens With ADHD Start Driving

Teens with attention-deficit/hyperactivity disorder (ADHD) are more likely than their peers to experience a car crash, get a speeding ticket, and drive without a license. That is not new news. But what is new is the degree of that risk.

A recently published retrospective cohort study^[1] used electronic health record (EHR) data on almost 15,000 teenagers from six primary care practices in New Jersey. These data were merged with data from the state's motor vehicle commission as well as police departments to identify licensure and crash events, ultimately identifying from this cohort 1769 adolescents with ADHD and a New Jersey driving license (approximately 12% of the entire sample). The investigators then compared traffic events between this group and the remaining group that did not have an ADHD diagnosis.

The state tries to keep teen drivers safe. Teenagers may obtain a driver's license at 17 years of age. However, they are prohibited from driving overnight, using electronics while driving, or having more than one peer in the car for the first year of driving.

The study investigators used state records to evaluate:

All crashes reportable to the police;
Crashes with an injury;
Crashes for which the adolescent was at fault;
Crashes at night;
Crashes with a passenger in the vehicle;
Single vehicle crashes; and
Crashes that involved alcohol.

They then compared the teens identified from EHRs as having ADHD with teens who did not have this condition. Kids with ADHD were slightly older when they obtained their license (median, 17.3 years vs 17 years). Males made up 72% of the ADHD group compared with 49.9% of all teens.

Three times as many adolescents with ADHD had a seizure disorder compared with those without ADHD (3.3% vs 1.1%). Multivariable analysis was used to account for this difference.

Adolescent drivers with ADHD were more likely to experience a crash or moving violation at multiple time points from the first month of driving all the way through 4 years of driving experience (Table). This same pattern held for all subtypes of crashes, moving violations, and license suspensions, including those involving alcohol or resulting in a moderate or severe injury. The only exception was for nighttime crashes, for which no difference was found.

Table. Crashes and Traffic Violations Among Teens With and Without ADHD

Event	With ADHD	Without ADHD	P Value
Traffic crashes within first month of driving	2.8%	1.9%	.007
Traffic crashes within 12 months	19.8	16.2%	< .001
Traffic crashes within 48 months	46.8%	36.4%	< .001
All traffic violations within 12 months	35.6%	25.3%	< .001
All traffic violations within 48 months	73.2%	58.1%	< .001
Moving violations within 12 months	26.8%	18.6%	< .001
Moving violations within 48 months	62.8%	48.2%	< .001
License suspension within 48 months	17.1%	10.1%	< .001

ADHD = attention-deficit/hyperactivity disorder

Although all vehicular violations were more likely to occur among adolescents with ADHD, they were also distressingly prevalent among those without ADHD. By 48 months of driving, almost two thirds (62.8%) of the kids with ADHD had been cited for at least one moving violation, but so had almost half (48.2%) of those without ADHD. Speeding, careless driving, and driving without a seatbelt were all more common among kids with ADHD.

Viewpoint

So here is the dilemma: Do you share these numbers with parents or not? If you told parents that over one third of teens would be involved in a crash within 4 years of driving, I wonder how many parents would ever let their children drive.

No, it's not clear that these results would be generalizable to adolescents in other states, especially those with younger initial driving ages, more rural roadways, or a lack of graduated driving licensure. However, there is no reason to think that New Jersey teens are a unique bunch. In fact, because of the many restrictions placed on young drivers by the state, teens in New Jersey may be even safer—which is why some experts suggest that delaying the age of driving until a teen is potentially no longer under the purview of a state's restrictions on younger drivers may not be a good idea.^[2]

What about pharmacologic therapy for ADHD as a strategy to mitigate risk for a car crash? Previous research by this same group of investigators found no difference in crash risk by medication status.^[3] As a result, they emphasize the need for other, nonpharmacologic strategies.

I think the study authors' suggestion that we use these data to focus on the risky driving behaviors that appear more prevalent in adolescents with ADHD is a good one. But that doesn't mean we should not also discuss safe driving with all teenage drivers and their parents. Clearly, impaired attention alone is not the only factor contributing to the higher rates of crash and motor vehicle violations among kids with ADHD. However, working with parents and teens on automobile operation safety clearly falls under the umbrella of healthcare.

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