There has been an increase in the use of medications to treat attention deficit hyperactivity disorder (ADHD) in both adults and children between 2001 and 2015, a study involving over 154 million individuals from 14 countries in Europe, North America, Asia, and Australasia. The study provides the most comprehensive analysis yet of trends in ADHD medication use. The study was published in the journal The Lancet Psychiatry.

Global estimates suggest that ADHD affects 5% to 7% of children and around 2.5% of adults. While the use of ADHD medications in children and adolescents (aged 3-18 years) has gone up in all countries, the number of people using medication ranged from 0.3% in France to 6.7% among Medicaid beneficiaries in the USA in 2010.

Additionally, the wide and persistent disparities in use of these drugs between countries and regions, suggests marked differences in the clinical approach to treating ADHD, underscoring the need for evidence-based guidelines to be followed consistently in clinical practice so that individuals with ADHD receive optimal treatment.

ADHD Medications 

ADHD is one of the most common neurodevelopmental disorders in children. However, it can be a lifelong condition, and at least two-thirds of children continue to show symptoms in adulthood. They found that ADHD medications can be effective and safe treatment options for children, adolescents, and adults.

They believe increases in the prescribing of ADHD medications reflect improved awareness of ADHD and recognition of the importance of effective treatment to avoid long-term problems. In most countries these rates are considerably lower than ADHD prevalence estimates, indicating that many cases of ADHD may be going undiagnosed and untreated especially in nations in Asia where use is low.

ADHD Drugs

Despite concerns over the rising use of ADHD drugs and inappropriate prescribing of medications, little was known about the trends and usage patterns in different world regions, particularly among adults, before this latest research.

The rise in medication was most pronounced among children in Canada, with average increases of over 45% a year (from 0.2% of children using ADHD drugs in 2001 to 1.8% in 2009). In adults, growth in Japan has been faster than in other countries, with average increases of 76% a year (0.003% of adults in 2010 to 0.5% in 2015). However, despite large increases, overall medication use remains low.

The types of medications prescribed also varied. Methylphenidate was the most commonly prescribed drug for ADHD in all countries in 2010—ranging from more than 90% of patients in Hong Kong, Taiwan, Canada, Finland, and Spain to less than 60% in Australia, and 45% of US Medicaid patients.

Treatment

The main treatment for privately insured US patients (MarketScan) was amphetamine (41%), followed by methylphenidate (34%) and lisdexamfetamine (21%). The authors point to some limitations including that the data only relate to the proportion of individuals with at least one prescription in a calendar year and not to the proportion receiving treatment at any given time. 

Finally, the study examined medication use regardless of an ADHD diagnosis, so it is unclear what proportion of participants were prescribed medications for ADHD or hyperactivity symptoms in patients with other disorders such as autism.