Attention-deficit/hyperactivity disorder (ADHD) affects up to five percent of people worldwide. It is a neurodevelopmental condition characterized by distractibility, inattention, hyperactivity and impulsivity.

Stimulant medications such as amphetamines are often prescribed to treat ADHD symptoms. Though this may seem counterintuitive, they have been shown to improve health and social outcomes in people with the disorder. It is noteworthy, however, that prescriptions for stimulants to treat ADHD increased by 157 percent between 2015 and 2023, according to a new Canadian study.

Researchers in Ontario, Canada analyzed data from the Narcotics Monitoring System there and found prescriptions for stimulants were given to more than 15 million residents between 2015 and 2023. Those prescribed the drugs were between five and 105 years old, and their average age was about 42. About half of them were female.

Stimulant prescribing began increasing in 2020 by 28 percent a year between 2020 and 2023.

Several things may have contributed to this increase, Daniel Myran, lead author on the study, told TheDoctor. One factor could be related to changes in routines during the COVID-19 pandemic.

Before 2020, people had school- or work-related routines that provided structure in their lives and helped them manage their ADHD symptoms. The pandemic disrupted routines and people spent more time online for work, school or recreation, all of which could have contributed to ADHD symptoms.

“When the way school or work is being done gets disrupted, some of those management strategies get disrupted as well,” said Myran. Stimulant prescribing began increasing in 2020, with the number of stimulant prescriptions rising by 28 percent a year between 2020 and 2023, compared to 15 percent between 2015 and 2019.

A second factor that could have contributed to the rise in stimulant prescriptions is the more frequent diagnosis of ADHD in people who were previously un- or under-diagnosed.

Awareness of ADHD and online discussion about it also increased during the study period, Myran explained. This meant, for example, that people learned that the symptoms of ADHD do not always include the hyperactivity often associated with the disorder and that a much more common symptom was having difficulty paying attention. Inattention is often seen in women, an historically under-diagnosed population when it comes to ADHD.

When the team looked at women specifically, they found prescriptions for stimulants rose by more than 368 percent for women aged 18 to 24 years old and by about 421 percent for those 25 to 44 years old during the study period. As more women were prescribed stimulants, the proportion of women in most age groups taking those medications became greater than that of men. By 2023, almost seven percent of women between the ages of 18 and 24 had been prescribed stimulants in the past year compared to about five percent of men.

The misdiagnosis or overdiagnosis of ADHD is another factor contributing to the increases seen in stimulant prescriptions. The risk of misdiagnosis is that patients are getting the incorrect treatment for what they have, such as a severe mood or anxiety disorder that interferes with their ability to focus or pay attention. “When people are misdiagnosed, it is a missed opportunity for correct care to treat other mental health conditions,” said Myran.

Before 2020, people had school- or work-related routines that provided structure in their lives and helped them manage their ADHD symptoms. The pandemic disrupted these routines.

When people are over-diagnosed, they may be prescribed medication they don't need and that might not benefit them.

The boom seen in prescriptions for ADHD is worthy of concern. Stimulants, like all medications, have side effects. The common ones include a decrease in appetite and trouble sleeping. Some people, particularly if they don't have ADHD, may find that taking stimulants can make their anxiety worse or that they develop panic attacks.

Stimulants can also have serious cardiovascular side effects: They can raise blood pressure and long-term use can increase the risk of heart attack or stroke.

Myran, a family physician and research chair in family and community medicine at North York General Hospital in Ontario, said future studies could examine if stimulant medications still have educational and social benefits for patients in much larger populations.

The study is published in JAMA Network Open.