Objective: The burden of attention-deficit/hyperactivity disorder (ADHD) in adults is increasingly recognized. This retrospective analysis was designed to estimate the prevalence of diagnosed ADHD in a population of insured, employed individuals and their dependents in the United States.
Methods: Health care claims data obtained from the MarketScan Commercial Claims and Encounters Database were analyzed. Patients with ADHD were identified by at least two diagnostic claims per calendar year. Once identified, patient records were examined for evidence of continuing ADHD.
Results: Between 2002 and 2007, the MarketScan database identified 342,284 patients with more than one claim for ADHD. Of these, 79,368 patients met the eligibility for the prevalence estimates. During the study period, the prevalence of diagnosed ADHD among adults increased more than three-fold: 1.24 to 4.02 cases per 1000 covered members. The largest proportion of cases was in the 18-24 years age group (42.8%-45.8% per year). Most cases were males; however, the ratio of females-to-males diagnosed increased over time. ADHD with hyperactivity was prevalent across all age groups analyzed, although more common in the 18-24 years group. Pharmacy claims showed patients receiving medical treatment for ADHD increased from 78% to 88.5%. A limitation of this study is that it is restricted to employed persons and their dependents. Thus, the results from this database may underestimate the true prevalence of diagnosed ADHD in the US population.
Conclusions: While the claims database used included employed insured persons and dependents only, study results highlight the rising prevalence of diagnosed ADHD in a US adult population. The prevalence increased more than three-fold from 2002 to 2007 with the largest increase in the 18-24 years age group. These findings on ADHD prevalence highlight the need for greater attention to the medical treatment of this disorder in different age groups, particularly in young adults.