Driving is a dangerous undertaking for any adolescent. Automobile collisions account for 47% of all female and 37% of all male adolescent (16 to 19 years old) deaths in the United States.1 In 2002, the cost of police- reported crashes (both fatal and nonfatal) involving drivers aged 15 to 20 years was $40.8 billion.2These collisions are 4 times more likely to occur at night.3 In addition, they are twice as likely to take place on weekends4 and more likely to happen during the summer.3
While this is disturbing enough, driving becomes even more problematic for adolescents who have attention deficit hyperactivity disorder (ADHD). Teenage drivers with ADHD are 8 times more likely to lose their license, 4 times more likely to be involved in a collision, 3 times more likely to sustain a serious injury, and 2 to 4 times more likely to receive a moving vehicle violation.5,6 This is not surprising considering that the core symptoms of ADHD are inattention, impulsivity, and hyperactivity. Also, alcohol use commonly influences driving mishaps among adolescents; 24% of young drivers who died in crashes in 2002 had a blood alcohol level of 0.08% or higher.2 Given the same blood alcohol levels, persons with ADHD have been shown to be more impaired while driving than those without ADHD.7
The good news is that methylphenidate has been shown to improve the driving performance of adolescents with ADHD--both in virtual-reality driving simulators in which drivers are exposed to high-risk driving demands8 and routine on-road driving in their own vehicle.5 Ours is the only group that has published studies that compare the efficacy of different medications on driving performance in adolescents with ADHD. Preliminary study results indicate that controlled-release OROS methylphenidate taken once a day improves driving performance significantly more in the evenings than short-acting methylphenidate taken 3 times a day or long-acting mixed amphetamine salts taken once a day.8-10
In the only study that evaluated atomoxetine, the drug was found to improve self-reported driving ability but not simulated driving performance.11 Another pilot study suggests the arousal and attention demand of a manual transmission may enhance the attention of ADHD adolescent drivers and promote safer driving than automatic transmissions.12
Two other articles offer in-depth reviews.13,14
Initiating and Monitoring Therapy
Before considering treatment options, it might be useful to review the diagnosis of ADHD. The Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) outlines diagnostic criteria for childhood ADHD.15 We have converted these criteria to be adolescent-relevant (Table 1). To qualify for a diagnosis of ADHD, a patient must have had at least 6 symptoms in the inattentive or 6 symptoms in the impulsive/hyperactive categories in at least 2 areas of their lives (eg, school, work, home) since age 6. These behaviors must occur often, not just periodically. Adolescents may qualify for the inattentive, impulsive/hyperactive, or the combined subtype. Consider stimulant medication therapy only if the adolescent meets the criteria for one of these subtypes.
Treatment should involve a long-acting stimulant medication, which may need to be supplemented with short-acting methylphenidate if the adolescent drives more than 15 hours after ingesting OROS methylphenidate. The dosage should be increased until there is no further improvement in ADHD symptoms or unacceptable adverse side effects develop.
Clinicians typically strive to optimize the dosage of medication used to manage such chronic diseases as asthma and epilepsy. However, we sometimes adjust the dosage in patients with ADHD only until beneficial effect is detected. To evaluate whether symptoms are responding to the medication, it is not enough to rely on simple global reports, such as, "things are a lot better." It is more helpful to systematically review and record the symptoms shown in Table 1 before starting any medication, and then after each increase in medication dose. It is not unusual to find that one set of symptoms improves with a lower dose and a different cluster of symptoms improves with a higher dose. The patient, parent, and/or teacher may describe especially worrisome symptoms that also need to be monitored.
1. Insurance Institute for Highway Safety. Fatality Facts 2004: Teenagers. Available at: http://www.iihs.org/research/fatality_facts/pdfs/teenagers.pdf. Accessed December 6, 2006.
2. Traffic Safety Facts 2002. Young Drivers, National Highway Traffic Safety Administration, DOT HS 809 619. Available at: http://www-nrd.nhtsa.dot.gov/pdf/nrd-30/NCSA/TSF2002/2002ydrfacts.pdf. Accessed December 12, 2006.
3. National Center for Statistics and Analysis, National Highway Traffic Safety Administration. Fatality Analysis Reporting System (FARS) Web-based Encyclopedia. Available online at http://www-fars.nhtsa.dot.gov/main.cfm. Accessed December 6, 2006.
4. National Highway Transportation Safety Administration. Report--Teens at Risk. Available at: http://www-cdc.gov/ncipc/factsheets/teenmvh.htm. Accessed December 6, 2006.
5. Barkley RA, Murphy KR, Kwasnik D. Motor vehicle driving competencies and risks in teens and young adults with attention deficit hyperactivity disorder. Pediatrics. 1996;98:1089-1095.
6. Barkley RA, Guevremont DC, Anastopoulos AD,
et al. Driving-related risks and outcomes of attention deficit hyperactivity disorder in adolescents and young adults: a 3- to 5-year follow-up survey. Pediatrics. 1993;92:212-218.
7. Barkley RA, Murphy KR, O'Connell T, et al. Effects of two doses of alcohol on simulator driving performance in adults with attention-deficit/hyperactivity disorder. Neuropsychology. 2006;20:77-87.
8. Cox DJ, Merkel RL, Moore M, et al. Relative benefits of stimulant therapy with OROS methylphenidate versus mixed amphetamine salts extended release in improving the driving performance of adolescent drivers with attention-deficit/ hyperactivity disorder. Pediatrics. 2006;118:e704-e710.
9. Cox DJ, Humphrey JW, Merkel RL, et al. Controlled-release methylphenidate improves attention during on-road driving by adolescents with attention-deficit/hyperactivity disorder. J Am Board Fam Pract. 2004;17:235-239.
10. Cox DJ, Merkel RL, Kovatchev B, Seward R. Effect of stimulant medication on driving performance of young adults with attention-deficit/hyperactivity disorder: a preliminary double-blind placebo controlled trial. J Nerv Ment Dis. 2000;188:230-234.
11. Barkley RA, Anderson DL, Kruesi M. A pilot study of atomoxetine on driving performance in adults with attention deficit hyperactivity disorder (ADHD). J Atten Disord. 2006. In press.
12. Cox DJ, Punja M, Powers K, et al. Manual transmission enhances attention and driving performance of ADHD adolescent males: pilot study. J Atten Disord. 2006;10:212-216.
13. Jerome L, Habinski L, Segal A. Attention-deficit/ hyperactivity disorder (ADHD) and driving risk: a review of the literature and a methodological critique. Curr Psychiatry Rep. 2006;8:416-426.
14. Barkley RA, Cox D. A review of driving performance and adverse outcomes in adolescents and adults with attention deficit/hyperactivity disorder. J Safety Res. 2007. In press.
15. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Association; 2000:85-93.
16. Quillian WC, Cox DJ, Kovatchev B, Phillips C. The effects of age and alcohol intoxication on simulated driving performance, awareness and self- restraint. Age Ageing 1999;28:59-66.
17. Cox DJ, Tisdelle DA, Culbert JP. Increasing adherence to behavioral homework assignments. J Behav Med. 1988;11:519-522.
18. Laberge J, Ward N, Manser M, et al. Driving skills among ADHD drivers: Preliminary research. Unpublished manuscript.