Attention Deficit Hyperactivity Disorder

Children and adolescents of different temperaments differ widely in their levels of physical activity, attentiveness, and self-control. High energy levels and impulsivity are a normal part of childhood and adolescence, and children and teens often react to acute stress with temporary inattention and overactivity.

However, when a child’s or teen’s levels of overactivity, inattention, and/or impulsivity are severe and persistent and interfere with his learning, fun, or relationships, he should be evaluated for attention deficit hyperactivity disorder (ADHD) and related problems.

Children and teens with ADHD can exhibit a range of problems. Some are mainly inattentive and may underperform in school and appear to be daydreamers, while others are hyperactive and impulsive. Many exhibit all three sets of ADHD symptoms: inattention, hyperactivity, and impulsivity.

These different sets of symptoms are reflected in the subtypes of ADHD: inattentive type, hyperactive and impulsive type, and combined type. Children who are hyperactive may come to clinical attention at an early age because of unsafe or hard-to-control behaviors, while children and teens who are mainly inattentive are often not identified.

Key Facts:

  • Attention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed mental disorders in U.S. children and adolescents. Five million children 3 to 17 years of age (8 percent) have ADHD. Boys are more than twice as likely as girls to have ADHD.1
  • There is no single diagnostic tool for ADHD. To diagnose the disorder, a health professional considers a child’s or teen’s history and symptoms and rules out other potential causes of inattention, hyperactivity, and impulsivity.
  • The exact cause of ADHD is not known. However, research indicates a strong genetic component is involved.2
  • Symptoms persist into adulthood in as many as 60 percent of cases (affecting approximately 4 percent of adults).3,4
  • Untreated, ADHD and its comorbid disorders can result in difficulties with family and peer relationships and achievement at school and work, substance abuse and accidental injuries.5


  1. Bloom, B., Cohen, R. A., & Freeman, G. (2008). Summary Health Statistics for U.S. Children: National Health Interview Survey, 2008. Vital and Health Statistics, 10 (244 Prov.).
  2. Barkley, R. A. (2006). Attention-Deficit Hyperactivity Disorder, Third Edition: A Handbook for Diagnosis and Treatment. New York, NY: The Guilford Press.
  3. Kessler, R. C., Adler, L., Barkley, R., & Biederman, J. (2006). The prevalence and correlates of adult ADHD in the United States: Results from the National Comorbidity Survey Replication. American Journal of Psychiatry, 163, 724-732.
  4. Faraone, S. V., Biederman, J., & Mick, E. (2006). The age-dependent decline of attention-deficit hyperactivity disorder: A meta-analysis of follow-up studies. Psychological Medicine, 36, 159-165.
  5. Spencer, T. J., Biederman, J., & Mick, E. (2007). Attention-deficit/hyperactivity disorder: Diagnosis, lifespan, comorbidities, and neurobiology. Journal of Pediatric Psychology, 32 (6), 631-642.