Research on ADHD

Overview

Attention-deficit/hyperactivity disorder (ADHD) is a serious public health problem affecting a large number of children and adults. CDC conducts research to expand on what is known about ADHD. The information learned will improve knowledge about the factors that increase the risk for ADHD, as well as the causes, and best treatments, and will aid the development of resources to help people living with ADHD. Learn more about CDC’s research on ADHD on this overview page.

ADHD can cause problems in how well children do in school, in their ability to make and keep friends, and in how they function in society. Although there are treatments to improve ADHD symptoms, more information is needed about managing ADHD so that children can learn and grow into adulthood without being impaired by their symptoms.

Research on ADHD

The criteria used to diagnose ADHD have changed over time. Researchers who study ADHD have used different definitions to diagnose ADHD. This has led to some disagreement about the number, characteristics, and outcomes of children with the disorder. Although the exact causes of ADHD are not known, research shows that genes play a role, but other factors may contribute or make symptoms worse. There are many unanswered questions about ADHD, and there is more we need to learn about how ADHD affects people throughout their life.

The treatment costs of ADHD and the personal and societal costs can be significant. Researchers estimate that in the United States, $31.6 billion is the combined annual cost for

  • Health care for persons with ADHD specifically related to the diagnosis;
  • Health care for family members of persons with ADHD specifically related to their family member’s diagnosis; and
  • Work absences among adults with ADHD and adult family members of persons with ADHD.1

Improving the health of individuals with ADHD could result in substantial financial savings to families and society, potentially reducing this financial burden.

Current Research

National Surveys

CDC uses data from national surveys to understand the number of children with ADHD, other concerns and conditions they might experience, and the kind of treatment they might receive. Surveys that have data on children and on ADHD include

Read about key findings from the national surveys.

Learn more about the data from the national surveys.

Policy Research

Fast Fact: A policy research study found that 27 states manage access to ADHD medications for children.

In order to fully appreciate how children with ADHD are treated, one must understand the policies that affect how treatments are authorized and reimbursed by health plans. One policy that may affect medication treatment is for health plans or state programs to require pre-authorization before specific medications can be prescribed. Prescription prior-authorization policy means that the health plan or state program is required to review a physician’s prescription request before coverage for the medication is granted.

Over the past decade, the number of children being prescribed ADHD medications has increased substantially. In response to this trend, many state Medicaid programs have implemented prior-authorization policies for pediatric use of ADHD medications. These policies vary from state to state, and no comprehensive information on these policies was previously available.

To learn more about prior-authorization policies related to pediatric use of ADHD medications, CDC collaborated with Temple University to conduct a cross-sectional mapping study. Information was gathered on state Medicaid prior-authorization policies (as of November 2015) for prescribing ADHD medication to children. The study team collected

New Research: Medicaid policies to manage the use of ADHD medications: Information by state

Learn more

  • Prior-authorization forms,
  • Memoranda from state Medicaid directors to prescribers,
  • Drug utilization review board meeting notes, and
  • State prescription drug lists.

The study team developed a coding scheme to capture and catalogue the key features of the prior-authorization policies. You can access a fact sheet with a summary of the results of this mapping study Cdc-pdf[PDF – 353 KB] and also a database of state policies.

A list of readings and resources on ADHD treatment policy options, including information on Medicaid drug prior authorization and reimbursement for behavioral therapy Cdc-pdf[PDF – 360KB], is available.

Healthcare Claims Data

CDC uses healthcare insurance claims data to understand treatment patterns for children in clinical care for ADHD, such as claims for psychological services and ADHD medication in patients covered by employer-sponsored insurance or by Medicaid.

Read more about the data from healthcare claims datasets.

Community-based Research

CDC’s National Center on Birth Defects and Developmental Disabilities (NCBDDD) is funding large community-based, epidemiologic studies of ADHD in the United States. These studies

  • Enhance what is known about ADHD and the co-occurring conditions in children and
  • Increase the opportunity to make the most informed decisions and recommendations about potential public health prevention and intervention strategies for children with ADHD.
Project to Learn About Youth – Mental Health
Project to Learn about Youth PLAY logo

The Project to Learn About Youth – Mental Health (PLAY-MH) is taking place in four communities. This project uses the same methodology as the original Project to Learn About ADHD in Youth (PLAY) project, but expands the focus to study a range of mental, behavioral, or emotional disorders including ADHD and tic disorders (such as Tourette syndrome). The project will provide valuable information that can be used for public health prevention and intervention strategies to support children’s health and development.

Study questions include

Project to Learn About ADHD in Youth (PLAY)
Project to Learn About ADHD in Youth (PLAY)

The Project to Learn About ADHD in Youth (PLAY) was a population-based research project with the University of South Carolina and the University of Oklahoma Health Sciences Center. It was conducted to shed more light on how many school-age children have ADHD, how the condition develops over time, what other conditions and risks children may experience, and about treatments they may receive. Data were collected to learn more about ADHD in diverse population groups, the quality and patterns of treatment, and the factors that affect short- and long-term outcomes for children.

Learn more about the original PLAY study.

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Understanding Risk

Boys

It is not known what causes ADHD. ADHD is often seen in families, and genes appear to play a role, but other factors may contribute or make symptoms worse. For example, some environmental exposures have been linked to increased ADHD symptoms, but the evidence has been inconsistent. Knowing more about those factors would help with planning how to decrease the risk for ADHD. NCBDDD funded a comprehensive literature review of studies that investigate a large range of factors that might increase the risk for ADHD. The results will increase the ability of public health professionals to make the most informed decisions and recommendations about potential public health prevention strategies.

Research Agenda

Public health issues in ADHD can be divided into three areas:

  • Understanding how many children have ADHD and whether they are properly diagnosed.
  • Understanding and addressing the impact of ADHD in the population.
  • Understanding which treatments are effective and which are best for children of different ages and in different communities.

Key public health questions yet to be answered include

  • What are the causes, and the factors that increase the risk or severity of ADHD?
  • How many children have ADHD? Is the rate increasing?
  • How many children have ADHD and other conditions at the same time?
  • What social and economic impacts does ADHD have on families, schools, the workforce, and the judicial and health systems?
  • Are ADHD and other co-occurring conditions conditions being appropriately diagnosed and treated?
  • Are people with ADHD able to access appropriate and timely treatment?
  • How effective are the treatments and what are their long-term effects?

Previous Workshop Summaries

References

Birnbaum HG, Kessler RC, Lowe SW, Secnik K, Greenberg PE, Leong SA, et al. Costs of attention deficit-hyperactivity disorder (ADHD) in the US: excess costs of persons with ADHD and their family members in 2000. Current medical research and opinion 2005;21(2):195-206External.