Prescription stimulant drug trends in Ontario, Canada, 2015-24: population based repeated cross sectional study

Objective — To examine current population level changes in prescriptions for stimulant drugs in Ontario, Canada.

Design — Population based repeated cross sectional study.

Setting — Ontario, Canada.

Participants — 15 091 342 Ontario residents, aged 5-105 years, who were eligible for the Ontario Health Insurance Plan between 1 January 2015 and 31 December 2024; 563 632 (3.7%) participants had at least one prescription for a stimulant during the study period.

Main outcome measures — Annual incidence of stimulant prescriptions in Ontario, defined as the number of individuals each year with a newly dispensed prescription for a stimulant drug, with no record of any stimulant prescription in the previous three years, by use of the Narcotics Monitoring System database, which captures all stimulant drug prescribing in Ontario. Secondary outcome was percentage of individuals with a past year stimulant prescription.

Results — Incident stimulant prescriptions increased by 170.1% between 2015 and 2024 (275.3 to 743.4 per 100 000 individuals). Incident prescriptions increased by 7.4% each year (95% confidence interval (CI) 3.3% to 11.7%) between 2015 and 2019, and increased further between 2020 and 2024 by 22.6% each year (17.8% to 27.7%). Increases were greater in female individuals than in male individuals, with the largest increases between 2015 and 2024 occurring in those aged 35-44 years (434.4% in women and 261.4% in men), and the smallest increases occurring in adults aged ≥65 years (40.0% in women and 13.5% in men) and in young people aged 5-9 years (79.5% in girls and 45.2% in boys). In 2024, the prevalence of past year stimulant prescriptions was 3.0% for the whole population, with the highest level at 8.3% in boys aged 10-14 years and 7.3% in women aged 18-24 years. Comparable increases in incident prescriptions were observed in both urban and rural settings, across neighbourhood income groups, and by immigration status, and increases were greater in individuals without a history of care for comorbid mental health conditions (183.0% v 92.5%).

Conclusions — The rate of stimulant prescriptions in Ontario nearly tripled over the past nine years, with the largest increases occurring in female individuals and adults since 2020. Further research is needed to understand the possible causes of these trends, which include an increase in the number of individuals with attention deficit/hyperactivity disorder (ADHD) or related symptoms, improved identification of undiagnosed ADHD, or overdiagnosis of ADHD, along with health effects associated with increasing use of stimulants.