Over the past 20 years, the prevalence of attention-deficit/hyperactivity disorder (ADHD) has increased significantly in the United States. A study published in JAMA Network Open noted that from 1997 to1998 through 2015 to 2016, the prevalence among children and adolescents increased from 6.1% to 10.2% (P for trend <0.001).
Gulfeng Xu, MD, of the Center for Disabilities and Development, University of Iowa Stead Family Children’s Hospital, and the Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, and colleagues conducted an analysis of the National Health Interview Survey, a population-based cross-sectional survey. They included 186,457 children and adolescents age 4 to 17 years in the analysis. The main outcome was ADHD diagnosed by a physician or other healthcare professional.
The authors found significant differences in the prevalence of ADHD by age, sex, race/ethnicity, family income, and geographic area. Among children age 4 to 11 years, the prevalence was 7.7%. This rose to 13.5% for adolescents age 12 to 17 years. Among boys, the prevalence was 14.0% compared with 6.3% in girls. Hispanics had an overall prevalence of 6.1%, whereas in non-Hispanic whites, that figure was 12.6%, and for non-Hispanic blacks it was 12.8%. Regional differences were evident as well — in the Northeast, the prevalence was 10.3%, in the Midwest 12.2%, in the South 11.1%, and in the West 7.0%. All subgroups demonstrated a significant increase in prevalence over the 20-year period. Studies conducted in the United Kingdom have also shown a significant increase over this period; however, increases in the United States have been substantially greater.
The authors suggest that this may be the result of expanded continuing medical education regarding ADHD that has raised physician awareness. Modifications in diagnostic criteria may also have contributed to the increase, and better access to health care may have resulted in increases in diagnoses among black and Hispanic children.
One important study limitation was the use of parent-reported physician diagnosis, which may be subject to misreporting and recall bias.
The authors call for better understanding of potentially modifiable risk factors and sufficient resources for the diagnosis and treatment of individuals with ADHD.
Xu G, Strathearn L, Liu B, Yang B, Bao W. Twenty-year trends in diagnosed attention-deficit/hyperactivity disorder among US children and adolescents, 1997-2016. JAMA Network Open. 2018;1(4):e181471.