Features of Attention-Deficit Hyperactivity Disorder (ADHD)

Features of Attention-Deficit Hyperactivity Disorder (ADHD)


The previous two posts described how Attention-Deficit Hyperactivity Disorder (ADHD) is diagnosed. This post will discuss other clinical features of ADHD.


The prevalence of a disease is defined as the number of individuals diagnosed with the disease compared to all individuals in a given population during a period of time. For example, among school-aged children, ADHD has a worldwide prevalence of about 5%.1 That is, an estimated 5 out of every 100 children have a diagnosis of ADHD. However, the prevalence of ADHD in the United States appears to be higher than the worldwide prevalence at 7%-9%.2 It is not clear why the United States has higher numbers of children with ADHD, but it is probably related to differences in diagnostic and study methods rather than true regional differences in ADHD symptoms.1

So, is ADHD overdiagnosed in the United States? ADHD diagnoses increased by 42% from 2003 to 2011.2 This change is likely the result of heightened awareness and recognition of ADHD symptoms by healthcare providers as well as by parents and teachers. However, despite some public concerns about overdiagnosis and overtreatment, many children with ADHD are not sufficiently treated.3 Treatment improves functioning, so correct diagnoses and adequate treatments should be sought in every patient.


Why is adequate treatment important? Studies have shown that untreated (and undertreated) patients with ADHD are at higher risk of other problems, including the following:

  1. Automobile accidents
  2. School difficulties 
  3. Suicidal thoughts
  4. Incarceration
  5. Risky sexual behaviors
  6. Work difficulties (among older patients)
  7. And increased medical burden from smoking, obesity, medical nonadherence, and comorbidities

Comorbidities were defined in previous posts about ADHD and Tourette syndrome. A comorbid condition is an additional medical problem found commonly with the primary condition.

Additionally, ADHD symptoms – by definition (see earlier posts about diagnosis) – interfere with daily function. Treatment can improve social development, academic performance, and family cohesion.


Decades ago, it was thought that all ADHD symptoms resolved in adulthood. However, Longitudinal studies (studies following patients over time) from the 1990s firmly established that ADHD symptoms can persist in some patients. When diagnosed in childhood, about 80%-85% continue to experience symptoms as adolescents and about 60% continue to experience symptoms as adults.


Is ADHD overdiagnosed and overtreated? From a healthcare perspective, the better question seems to be whether children, adolescents, and adults who are correctly diagnosed with ADHD are adequately treated, since treatment can improve functioning and can decrease risks of other problems.


The next posts will describe medicine and non-medicine treatment options for ADHD.


1Polanczyk G, de Lima MS, Horta BL, Biederman J, Rohde LA. The worldwide prevalence of ADHD: a systematic review and metaregression analysis. Am J Psychiatry. 2007;164:942-948.

2Visser SN, Danielson ML, Bitsko RH, Holbrook JR, Kogan MD, Ghandour RM, Perou R, Blumberg SJ. Trends in the parent-report of health care provider-diagnosed and medicated attention-deficit/hyperactivity disorder: United States, 2003-2011. J Am Acad Child Adolesc Psychiatry. 2014;53:34-46.

3Manos MJ, Giuliano K, Geyer E. ADHD: Overdiagnosed and overtreated, or misdiagnosed and mistreated? Cleve Clin J Med. 2017 Nov;84(11):873-880.