Attention-Deficit/Hyperactivity Disorder (ADHD) is one of the most common childhood behavioral disorders and may affect more than two million children and adolescents in the United States.

What is ADHD?

According to the 1994, Diagnostic and Statistical Manual of Mental Disorders, Ed. IV, (DSM-IV) ADHD is a Disruptive Behavior Disorder characterized by the presence of a set of chronic and impairing behavior patterns that display abnormal levels of inattention, hyperactivity, or their combination. The symptom checklist below provides the specific criteria for making the diagnosis:

• Either 1 (Inattention) or 2(Hyperactivity-Impulsivity)
• Behavior has persisted for at least six months and to such a degree that it is maladaptive and inconsistent with developmental level. Must present with six or more of the following:

1. Inattention

a) often fails to give close attention to details or makes careless mistakes in schoolwork, work, or other activities

b) often has difficulty sustaining attention in tasks or play activities

c) often does not seem to listen when spoken to directly

d) often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (not due to oppositional behavior or failure to understand instructions)

e) often has difficulty organizing tasks and activities

f) often avoids, dislikes, or is reluctant to engage in tasks that require sustained mental effort (such as schoolwork or homework)

g) often loses things necessary for tasks or activities (toys, school assignments, pencils, books, or tools)

h) is often easily distracted by extraneous stimuli

i) is often forgetful in daily activities

2. Hyperactivity-Impulsivity

Hyperactivity

a) often fidgets with hands or feet or squirms in seat

b) often leaves seat in classroom or in other situations in which remaining seated is expected

c) often runs about or climbs excessively in situations in which it is inappropriate ( in adolescents or adults, may be limited to subjective feelings of restlessness)

d) often has difficulty playing or engaging in leisure activities quietly

e) is often "on the go" or often acts as if "driven by a motor"

f) often talks excessively

Impulsivity

g) often blurts out answers before questions have been completed

h) often has difficulty awaiting turn

i) often interrupts or intrudes on others (e.g., butts into conversations or games)

The Division of Birth Defects, Child Development, and Disability and Health (proposed) has been examining the public health issues related to ADHD with the intent of developing a relevant research agenda for future research of the disorder by CDC and/or other public agencies. We have identified three areas for which there exists a lack of needed research to address public health issues in ADHD. These areas are 1.) individual, social, and economic burden of ADHD through the lifespan; 2.) epidemiologic issues; and 3.) public health concerns in the treatment of ADHD.

The Individual, Social, and Economic Burden of ADHD Through the Lifespan

Establishing the relative importance of a disease or disorder to public health policy and research involves an understanding of the impact it has on individual and social systems, as well as the associated costs. Little scientific research has addressed the cost of ADHD to the individual or society. Additionally, a framework to address the scope of economic consequences attributable to ADHD has not been adequately formulated to quantify the individual and social burden of ADHD in our society. Because of the many short- and long-term manifestations of the condition, the costs can be both direct and indirect, and can arise in myriad ways.

Epidemiologic Issues in ADHD

The science of public health is epidemiology and this type of research uses population-based methods to identify etiologic pathways to disease or disorder development. It also provides the foundation for research in prevention, risk-factor analysis, and other relevant areas. Little rigorous scientific study of comorbidity, etiology, risk factors, or prevention of ADHD has been completed and the studies available have relied heavily on clinic-based populations rather than on population-based sampling. However, such rough estimates of comorbidity, secondary conditions, and health risk behaviors among those with Attention-Deficit Hyperactivity Disorder (ADHD) are quite high and range from 30 to 60 percent for highly comorbid conditions. ADHD is a very prevalent childhood disorder with a number of commonly comorbid conditions that present or develop in time with significant additional social, learning, and psychological impairment.

Prevalence estimates of Attention-Deficit/Hyperactivity Disorder (ADHD) have historically varied over time ranging from as low as under 1% to as high as nearly 20% of school-age children. There is no systematic monitoring of ADHD, no gold standard for epidemiologic research of the disorder, and minimal population-based epidemiologic research of ADHD in the United States. Consequently, even rough estimates of the prevalence provide no meaningful indication of the level of burden this disorder poses in our society. Unfortunately, current research endeavors provide insufficient information to explore, even roughly, basic descriptive epidemiologic questions such as how the disorder may vary by race, ethnicity, socio-economic status, and age. Currently there is no known etiology for the disorder; therefore, epidemiologic research is imperative. However there is a paucity of such rigorous science in the ADHD field.

Public Health Concerns in the Treatment of ADHD

The identification and treatment of both children and adults with ADHD is a very politicized and controversial topic. Due to the potential magnitude of the problem, especially among our nation’s youth, and the consequences of large numbers of persons seeking and/or receiving treatment at any given time, long-term outcomes (risks and benefits) of treatment should be monitored to ensure safety and optimal functioning where possible. The most common treatment is the psychopharmacological agent methylphenidate. Due to the lack of research of the long-term efficacy (greater than 24 months and in preschool populations), and safety of such treatment at the population level, a public health perspective should be applied to the treatment of ADHD. The lack of such research, coupled with an increase in length of treatment during the formative growth years, a decrease in the age of initiation into treatment, and growing prevalence estimates, are all causes for concern. As treatment options are considered, it is apparent that more reliance is placed on pharmaceutical remedies than on psychological interventions such as behavior modification, although the latter have been shown to have beneficial effects. This emphasis is apparent even without adequate evidence of long-term academic and functional improvements from pharmacological interventions.

An additional concern in the treatment of ADHD is the issue of comorbidity. Comorbid conditions and health risk behaviors associated with ADHD are often not identified or treated appropriately and those factors result in a significantly higher social cost burden, increased risk for poor educational attainment, and compromised social integration. A public health perspective must be applied to this disorder in a manner that acknowledges and addresses the high risk for comorbidity, secondary conditions, and participation in significant health risk behaviors associated with impulsive and inattentive behavior.

For More Information:

Developmental Disabilities Branch
Division of Birth Defects, Child Development, 
and Disability and Health
National Center for Environmental Health
Centers for Disease Control and Prevention
4770 Buford Highway NE
Mailstop F-15
Atlanta, Georgia 30341-3724
Phone:770/488-7360
FAX: (770) 488-7361
Email: ncehinfo@cdc.gov