UC Berkeley Press Release
Use of ADHD medication soars worldwide
BERKELEY – The use of psycho-stimulant drugs to treat attention-deficit/hyperactivity disorder (ADHD) has more than tripled worldwide since 1993, challenging widespread assumptions that this neuro-developmental disorder is concentrated in the United States, according to new research from the University of California, Berkeley.
While the United States, Canada and Australia showed higher-than-expected rates of ADHD medication use between 1993 and 2003, a country-by-country analysis showed increases in ADHD drug consumption in countries including France, Sweden, Korea and Japan.
The study, published today (Tuesday, March 6) in the journal Health Affairs, examined ADHD medication use among 5- to 19-year-olds in countries belonging to the Organization for Economic Cooperation and Development (OECD), whose members are largely North American, European and Northeast Asian nations.
According to its authors, the findings, which reflect global trends, make a strong case for further studies on the long-term benefits of ADHD medications, as well as for an international exchange of ADHD data to better determine effective monitoring and treatment of this disorder.
Roughly one in 25 children and adolescents in the United States is taking medication for ADHD, said lead author Richard Scheffler, Distinguished Professor of Health Economics & Public Policy at UC Berkeley and director of the campus's Nicholas C. Petris Center on Health Care Markets and Consumer Welfare.
"Given the global diffusion of ADHD medications, as well as the prevalence of this condition, ADHD could become the leading childhood disorder treated with medications across the globe," Scheffler said. "We can expect that the already burgeoning global costs for medication treatment for ADHD will rise even more sharply over the next decade."
ADHD is characterized by poor concentration, distractibility, hyperactivity, impulsiveness and other symptoms that are age-inappropriate. If untreated, it can result in learning difficulties, volatile peer relationships and poor organizational skills.
Although the United States undeniably leads the world in ADHD medication spending ($2.4 billion in 2003), growth trends indicate that other countries are following in its tracks, according to the study. For example, global spending on ADHD medications increased nine-fold among OECD countries during the time period studied. This increase is largely due to the advent and availability of more costly and long-acting medications such as Concerta, Strattera and Adderral XR, the study says.
"ADHD medication treatment globally is becoming similar to that seen in the United States," said Dr. Peter Levine, a pediatrician with Kaiser Permanente in Walnut Creek and co-author of the study. "But the use of medications outside the United States is still primarily the less expensive, short-acting stimulant medications. Costs are likely to rise globally as long-acting medications, which offer easier use and result in better compliance, become more prevalent outside the U.S."
Using the IMS Health MIDAS, an international pharmaceutical database, researchers looked at data from nearly 70 countries. They found that between 1993 and 2003, the number of countries using ADHD medications rose from 31 to 55, with the U.S. share of the global market decreasing from 86.8 percent to 83.1 percent. Meanwhile, countries with traditionally low and moderate consumption of ADHD drugs were showing steady upswings.
The results temper some key criticisms of ADHD, said Stephen Hinshaw, chair of UC Berkeley's Department of Psychology and another co-author of the study.
"A common misconception is that ADHD only exists in the U.S. and that the pharmaceutical firms are getting bigger sales because of the 'creation' of the disorder in the U.S.," said Hinshaw, who investigates ADHD in children and adolescents. "Yet, cross-cultural research has shown that ADHD exists in all cultures, with increased access to public education a factor in its detection. Clearly, ADHD - which has a substantial genetic liability - is not just a figment of American doctors' imaginations."
Although stimulant medications such as methylphenidate and dextroamphetamine can be abused because of their ability to improve study skills and trigger euphoria, Hinshaw said, that abuse is marginal in comparison to the valid therapeutic use of the drugs. Still, he cautioned, careful diagnosis and careful monitoring of medications are essential, and behavioral treatments are also a viable alternative or complement to medication intervention.
The study recommends that countries compare data on use and spending to adjust overuse or under-use, and that they weigh carefully the potential benefits versus potential liabilities, such as side effects and addiction.