Study finds dramatic increase in ADHD medication use

Annual prescriptions for drugs to treat attention-deficit/hyperactivity disorder (ADHD) increased 157 percent in Ontario from 2015 to 2023, according to a new study from researchers at ICES, North York General, and The Hospital for Sick Children (SickKids). 

ADHD is a common neurodevelopmental disorder that affects approximately 1.6 to 5 percent of people worldwide. Stimulant medications such as amphetamines are often prescribed to treat the symptoms of ADHD and can lead to improvements in health and social outcomes in people with ADHD. 

"The upward trend in prescriptions around the world highlights an important challenge," says Dr. Daniel Myran, a family physician, ICES scientist, and Research Chair in Family and Community Medicine at North York General. "On one hand, it is likely showing progress towards identifying and treating ADHD in groups who have historically been underdiagnosed. However, the size of the increases also raises concerns about mis- or over-diagnosis, which can result in exposure to adverse side effects of medications and a missed opportunity to treat other mental health conditions."

The study included over 15 million people aged 5 to 105 years old living in Ontario, Canada, and found that 591,224 individuals (4 percent) had one or more stimulant prescriptions. 

Key findings: 

• Overall annual new stimulant prescriptions increased by 157.2 percent, from 275 per 100,000 individuals in 2015 to 708 in 2023. 

• Stimulant prescriptions accelerated in 2020, increasing 28 percent per year between 2020 and 2023, compared to only 7 percent from 2015 to 2019. 

• Stimulant prescriptions increased much more in women and in those aged 18-44. Over the study, stimulant prescriptions increased by 421.3% and 368.7% in females aged 25-44 and 18-24 respectively. 

• Greater increases in stimulant prescribing in females resulted in the prevalence in females exceeding that of males for many age groups. By the end of the study, 6.7% of females aged 18-24 had one or more stimulant prescriptions in the past year compared to 5.2% of males. 

One of the limitations of the study was a lack of data on whether the medication was being prescribed appropriately. 

The authors suggest several explanations for the increase in stimulant prescribing. First, that there has been a true rise in the number of individuals with symptoms of ADHD or ADHD, possibly related to changing social and environmental conditions such as greater use of screens and online content engagement for work and recreation. Second, improvement in the identification of undiagnosed ADHD, particularly in groups historically less recognized for ADHD. Third, misdiagnosis or overdiagnosis.

"The acceleration in 2020 coincides with the COVID-19 pandemic during which there was a large increase in online content about adult ADHD diagnoses and the emergence of private virtual clinics offering rapid ADHD assessments, says Myran. "These changes may both increase awareness and reduce barriers to diagnosis for people who have ADHD, but also increase the risk of overdiagnosis." 

"With around seven per cent of children and a nearly three-fold increase in adults being prescribed stimulants for ADHD than before the pandemic, ongoing research and clear clinical guidance are essential to ensuring these medications are used safely and appropriately," says Dr. Yaron Finkelstein, Staff Physician, Senior Scientist in the Child Health Evaluative Sciences program, Canada Research Chair in Pediatric Drug Safety and Efficacy, and the study's senior author.