Attention deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental condition that affects how the brain develops and functions. It's usually noticed in childhood, and more than half of those diagnosed keep experiencing symptoms as adults. Medicines for ADHD can reduce these symptoms, but lasting benefits depend on continuing the medication regularly.
In a new thesis from Karolinska Institutet, PhD student Honghui Yao has looked at ADHD medication and especially on why people stop their medication and how these patterns differ by age, sex, or country. As earlier studies have shown that people with ADHD are more likely to develop heart and metabolic problems, Honghui has also studied how ADHD itself and the medication affect people who already have heart‑related diseases.
What are the most important results in your thesis?
"When we looked at people with and without ADHD who had a heart attack, we saw that their medical history and health measurements were mostly the same. But people with ADHD were more likely to smoke and use snus, were less likely to attend follow‑up visits, and were less likely to quit smoking afterward.
For patterns on how people of different ages stopped or continued ADHD medication, we found that children were the least likely to stop, while young adults were the most likely to discontinue. Many people who stopped later started again, and when we included these restarts, more people stayed on treatment over time. After five years, about 50-60% of children and 30-40% of teenagers and adults were still receiving medication in most countries.
When we examined the associations of ADHD and ADHD medication use with adherence to antihypertensive medication, we found that individuals with ADHD were more likely to discontinue their antihypertensive medication."
Why did you become interested in this topic?
"I became interested because ADHD is common and often treated with medication, yet we are still learning about its long-term health effects - especially on the heart and metabolism. As research began to show that people with ADHD may face higher risks of cardiovascular and metabolic problems, I wanted to better understand how both the condition itself and its treatments influence long-term health, particularly in patients who already have heart-related diseases."
What do you think should be done in future research?
"In future health care and research, we should focus more on people who live with both ADHD and cardiovascular disease. We need stronger evidence on how ADHD medications affect this group in real-world settings - including their benefits, potential risks, and long-term outcomes. It is also important to study how clinicians choose the most appropriate medication for individuals with both ADHD and heart conditions, taking into account their overall health profile and treatment needs."
