Is attention-deficit hyperactivity disorder (ADHD) diagnosed in adults? An examination of US office-based physician visits, 1995-2000

Objective: To evaluate whether the trend in adults seeking medical care for the treatment of attention-deficit hyperactivity disorder (ADHD) reflects the upward pattern seen among children. Methods: Data from the US National Ambulatory Medical Care Survey were utilised for this analysis. The number and rate of office-based physician visits resulting in a diagnosis of ADHD (International Classification of Diseases, 9th Revision, Clinical Modification code 314.00 or 314.01) among patients aged ≥20 years were discerned for the years 1995-2000. Trend analyses were conducted using three time intervals: 1995-96, 1997-98 and 1999-2000. Results: Over the 6 years examined, national estimates of the number of annualised office-based physician visits documenting a diagnosis of ADHD among adults increased: 582 728 (95% CI 328 937, 836 518) in 1995-96; 611 703 (95% CI 348 475, 874 931) in 1997-98; and 1 049 486 (95% CI 518 776, 1 580 196) in 1999-2000. Adjusted for population growth, the rate per year of office-based visits per 1000 US population aged ≥20 years resulting in a diagnosis of ADHD was 3.1 in 1995-96, 3.2 in 1997-98 and 5.4 in 1999-2000. The majority of visits over the three time intervals documented a prescription for stimulant pharmacotherapy (61.0-69.6%). The mean age was 38 years, men accounted for 55.4% of the office visits and 75.1% of the visits were reported by psychiatric specialists. Conclusion: As with children, the rate of adults seeking medical care for ADHD increased between 1995 and 2000, with adults being treated predominantly with stimulant pharmacotherapy. Although this disorder was previously thought to be nonexistent in adults, by 1999-2000 adults accounted for nearly one in five (19.4%) US office visits resulting in a diagnosis of ADHD. © 2004 Adis Data Information BV. All rights reserved.