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How Common is Attention Deficit Hyperactive Disorder and Why is it Important to Treat?

Attention Deficit Hyperactivity Disorder, or ADHD,  is the most common neurodevelopmental disorder among children in North America. As a physician that sees ADHD in my practice, I wonder how common ADHD is and the effects of undiagnosed ADHD.

How common is ADHD? 

It is estimated that nearly 10% of all American children between 4 to 17 years old are affected by ADHD.  The reported rates vary depending on the diagnostic criteria used as well as the populations included in the studies. 

ADHD is more common in boys than girls.  Boys are more than twice as likely to have a diagnosis of ADHD than girls.  

Children with ADHD are also more likely to have other psychiatric disorders along with ADHD.  These may include oppositional defiant disorder, anxiety, depression, among others.    

Why is the diagnosis of ADHD important?

ADHD serves as an important diagnosis for children.  Effective treatment is available for ADHD.  Undiagnosed or untreated can have serious, lifelong complications.  ADHD can interfere with a child’s ability to participate in school, trouble learning, and put them in physician danger due to impulsivity.  As adults, they may experience problems with the law, poor relationships, and even difficulty holding down a job.

Compared to children without ADHD, children with ADHD are at greater risk of:

  • Self-injury: Children with ADHD are more likely to engage in intentional, or unintentional self-harm.  This can include things like burning themselves or cutting themselves.  
  • Car Crashes: Are almost twice as likely to have motor vehicle accidents when they begin to drive.
  • Worse School PerformanceChildren with ADHD are more likely to drop out of school, have lower academic achievement scores, and fail more courses.  This impairment persists even if the child no longer meets criteria for an ADHD diagnosis into adolescence or adulthood.  
  • Less likely to attend college or university: Data shows only 15-19% of adolescents with ADHD complete a bachelor’s degree, compared to 50-64% of adolescents without ADHD.
  • Drug use: Children with ADHD are over 2.5 times more likely to use substances like nicotine, alcohol, marijuana and cocaine in adolescence and adulthood.  

Perhaps it is unclear if the prevalence of ADHD is increasing or if we are just getting better at detecting it.  What is clear is that the timely diagnosis and treatment of ADHD is important for your child’s growth and development.  

If you think your child may have ADHD, please speak to your child’s doctor. 

This post was co-authored by Suzanne Black, MD, BSc, Stephanie Liu, MD, MSc, CCFP, BHSc and Erin Manchuk, BScPharm, BCGP 


  1. Mannuzza S, Klein RG, Bonagura N, et al. Hyperactive boys almost grown up. II. Status of subjects without a mental disorder. Arch Gen Psychiatry 1988; 45:13.
  2. Mannuzza S, Klein RG. Long-term prognosis in attention-deficit/hyperactivity disorder. Child Adolesc Psychiatr Clin N Am 2000; 9:711.
  3. Hinshaw SP, Owens EB, Zalecki C, et al. Prospective follow-up of girls with attention-deficit/hyperactivity disorder into early adulthood: continuing impairment includes elevated risk for suicide attempts and self-injury. J Consult Clin Psychol 2012; 80:1041.
  4. Curry AE, Metzger KB, Pfeiffer MR, et al. Motor Vehicle Crash Risk Among Adolescents and Young Adults With Attention-Deficit/Hyperactivity Disorder. JAMA Pediatr 2017; 171:756.
  5. 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.
  6. Verster JC, Bekker EM, de Roos M, et al. Methylphenidate significantly improves driving performance of adults with attention-deficit hyperactivity disorder: a randomized crossover trial. J Psychopharmacol 2008; 22:230.
  7. Biederman J, Fried R, Hammerness P, et al. The effects of lisdexamfetamine dimesylate on driving behaviors in young adults with ADHD assessed with the Manchester driving behavior questionnaire. J Adolesc Health 2012; 51:601.
  8. Weiss G, Hechtman L, Perlman T, et al. Hyperactives as young adults: a controlled prospective ten-year follow-up of 75 children. Arch Gen Psychiatry 1979; 36:675.
  9. Lambert NM. Adolescent outcomes for hyperactive children. Perspectives on general and specific patterns of childhood risk for adolescent educational, social, and mental health problems. Am Psychol 1988; 43:786.
  10. Fergusson DM, Lynskey MT, Horwood LJ. Attentional difficulties in middle childhood and psychosocial outcomes in young adulthood. J Child Psychol Psychiatry 1997; 38:633.
  11. Sayal K, Washbrook E, Propper C. Childhood behavior problems and academic outcomes in adolescence: longitudinal population-based study. J Am Acad Child Adolesc Psychiatry 2015; 54:360.
  12. Voigt RG, Katusic SK, Colligan RC, et al. Academic Achievement in Adults with a History of Childhood Attention-Deficit/Hyperactivity Disorder: A Population-Based Prospective Study. J Dev Behav Pediatr 2017; 38:1.
  13. Fleming M, Fitton CA, Steiner MFC, et al. Educational and Health Outcomes of Children Treated for Attention-Deficit/Hyperactivity Disorder. JAMA Pediatr 2017; 171:e170691.
  14. Boyle CA, Boulet S, Schieve LA, et. Al. Trends in the prevalence of developmental disabilities in US children, 1997-2008. Pediatrics 2011;127:1034-42
  15. Pastor PN, Reuben CA. Diagnosed attention deficit hyperactivity disorder and learning disability.  United States.  2004-2006.  Vital Health Stat 10 2008; 237:1-14.

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