Adult Stimulant Use Accounts for Most Recent Growth in ADHD Prescribing in Canada

Prescribing of stimulant medications for attention-deficit/hyperactivity disorder (ADHD) increased sharply in Ontario between 2015 and 2023, with particularly rapid growth after 2020 and disproportionate increases among women and adults aged 18 to 64 years.

In a population-level analysis of more than 15 million residents, investigators found that the annual incidence of stimulant prescriptions more than doubled over the study period, rising from 275.2 per 100 000 individuals in 2015 to 708.0 per 100 000 in 2023, for an overall increase of 157.2%. The findings were published online December 11 in JAMA Network Open.¹

According to study first author Daniel T Myran, MD, MPH, Canada Research Chair in Social Accountability at the Univesity of Ottowa, and colleagues, the pace of change accelerated markedly after the onset of the COVID-19 pandemic. Incident prescribing increased by an average of 29.2% per year from 2020 to 2023, compared with 7.4% annually from 2015 to 2019 (P_interaction <.001). Although stimulant use rose across nearly all demographic groups, the steepest relative increases occurred among young and middle-aged adults, and particularly among women.¹

Current Research

ADHD affects an estimated 1.6% to 5.0% of the global population,² and stimulant medications such as amphetamines remain a cornerstone of evidence-based treatment. Prior research links stimulant therapy to improvements in educational attainment, occupational functioning, and other long-term outcomes.³ At the same time, rising stimulant use in high-income countries has prompted concern about potential overdiagnosis, inappropriate prescribing, misuse, and adverse effects.¹

Much of the existing literature examining ADHD medication prescribing trends has relied on insurance claims data from commercially insured populations.^4,5 Myran et al sought to examine whether changes in stimulant prescribing were occurring at the population level and whether trends differed by age and sex. By using comprehensive administrative data from Ontario’s Narcotics Monitoring System, they aimed to capture real-world prescribing patterns across the full lifespan.¹

Study Design and Population

The population-based, repeated cross-sectional study included all Ontario residents aged 5 to 105 years who received a stimulant prescription between 2015 and 2023. The analysis captured both incident prescriptions, ie, no stimulant dispensing in the previous 3 years, and prevalent past-year use.

Negative binomial regression models estimated average annual percentage change (AAPC) overall and within age- and sex-stratified groups. The final cohort included 15 084 455 individuals (mean age, 42.3 years; 50.7% women), of whom 3.9% received at least 1 stimulant prescription during the study period.¹

Key Findings

Increases in stimulant prescribing occurred across nearly all demographic strata but varied substantially by age and sex, authors reported. Among adults aged 25 to 44 years, incident prescribing rose by 421.3% in women and 219.7% in men between 2015 and 2023. Adults aged 18 to 24 years experienced similarly large increases (368.7% in women; 127.6% in men), as did those aged 45 to 64 years (188.3% in women; 119.0% in men).

In contrast, increases were modest among children aged 5 to 9 years (49.1% in girls and 32.7% in boys) and minimal among adults aged 65 years or older (women 17.9%, men 2.3%). These patterns suggest that recent growth in stimulant use has been driven largely by adult prescribing rather than pediatric treatment.¹

Prevalence data from 2023 further underscore this shift. Overall, 2.6% of the Ontario population had a stimulant prescription in the past year. The highest prevalence occurred in males aged 10 to 14 years (7.8%) and women aged 18 to 24 years (6.7%). Notably, prevalence among women exceeded that of men in the 18- to 24-year (6.7% vs 5.2%), 25- to 44-year (3.8% vs 3.1%), and 45- to 64-year (1.4% vs 1.1%) age groups.¹

Authors' Thoughts on Trends

The authors propose several explanations for these findings. The increases may reflect true growth in ADHD prevalence or symptom burden, potentially influenced by social and environmental changes.¹ Expanded digital media use, online work, and screen-based recreation, patterns that intensified during the COVID-19 pandemic, have been associated with ADHD-related symptoms.⁶

At the same time, improved recognition of previously undiagnosed ADHD in adults may contribute to higher prescribing rates. The emergence of private virtual clinics offering ADHD assessments, along with increased public awareness through online content, may have lowered barriers to diagnosis.⁷The authors caution, however, that these same forces could also facilitate misdiagnosis or overdiagnosis.¹

Among the stuyd's limitations the authors acknowledged that administrative data do not allow assessment of diagnostic accuracy or prescription appropriateness. The analysis cannot distinguish between evidence-based treatment and potentially inappropriate use. In addition, the study does not capture clinical outcomes, symptom severity, or adherence, limiting interpretation of the observed trends’ clinical impact.1

Implications, The Future

The rapid growth of stimulant prescribing—particularly among adults and women—has implications for clinical practice, education, and policy. Prescription stimulants carry risks of cardiovascular events and other adverse outcomes regardless of indication. As adult ADHD diagnosis becomes more common, the authors emphasize the need for enhanced clinician training and clearer, evidence-based guidance for adult assessment and treatment.

Future research should focus on evaluating the appropriateness and outcomes of stimulant prescribing at the population level and on developing strategies to balance access to effective ADHD treatment with patient safety.¹

References

1. Myran DT, MacDonal-Spracklin R, Busa G, Talarico R, Finkelstein Y. Population-level trends in attention-deficit/hyeractivity disorder medication prescribing. JAMA Netw Open. 2025;8(12)::e2548532. doi:10.1001/jamanetworkopen.2025.48532

2. Popit S, Serod K, Locatelli I, Stuhec M. Prevalence of attention-deficit hyperactivity disorder (ADHD): systematic review and meta-analysis. Eur Psychiatry. 2024;67(1):e68. doi:10.1192/j.eurpsy.2024.1786

3. Shaw M, Hodgkins P, Caci H, et al. A systematic review and analysis of long-term outcomes in attention deficit hyperactivity disorder: effects of treatment and non-treatment. BMC Med. 2012;10:99. doi:10.1186/1741-7015-10-99

4. Han B, Jones CM, Volkow ND, et al. Prescription stimulant use, misuse, and use disorder among US adults aged 18 to 64 years. MMWR Morb Mortal Wkly Rep. 2023;72(13):329-336. doi:10.15585/mmwr.mm7213a1

5. Anderson KN, Ailes EC, Danielson ML, et al. Attention-deficit/hyperactivity disorder medication prescription fills among privately insured women aged 15–44 years — United States, 2003–2015. MMWR Morb Mortal Wkly Rep. 2018;67(2):66-70. doi:10.15585/mmwr.mm6702a3

6. Ra CK, Cho J, Stone MD, et al. Association of digital media use with subsequent symptoms of attention-deficit/hyperactivity disorder among adolescents. JAMA. 2018;320(3):255-263. doi:10.1001/jama.2018.8931

7. Yoon J. More adults think they have ADHD: but many are struggling to get diagnosed. CBC/Radio-Canada. October 26, 2024. Accessed October 27, 2025. https://www.cbc.ca/news/health/adult-adhd-undiagnosed-1.7363501