In the second of a series of three government-commissioned studies on the risks of popular drugs used to treat attention deficit hyperactivity disorder (ADHD), researchers report that the medications do not lead to increased risks of sudden death or heart events in adults. The research follows another study in children, published last month, which came to a similar conclusion.
The current study, led by Laurel Habel, a research fellow in epidemiology at Kaiser Permanente’s division of research, included data on more than 150,000 adults, aged 25 to 64, using medications like Adderall, Concerta, Strattera and Ritalin. The researchers found that, overall, those taking ADHD drugs were no more likely to have a heart attack, stroke or sudden death, compared with a matched group of non-users, during the study’s follow-up period.
The previous study, conducted by a separate group of scientists, showed similar results among 1.2 million children and younger adults taking ADHD medications.
Reports from doctors and patients in a federal database of adverse drug effects had suggested that ADHD medications, which work as stimulants, could cause a rise in blood pressure and heart rate, both of which are known to increase risk of heart attacks and heart disease. According to the Food and Drug Administration, about 1.5 million people took stimulants in 2005, and adults made up 32% of these prescriptions. Because older people are more vulnerable to heart conditions than young children, scientists were concerned about whether the drugs might be endangering people’s lives.
To find out, the researchers collated medical records from four study sites beginning in 1986 and followed patients for up to 19 years to record their ADHD medication use as well as cardiovascular events and sudden death. The data suggested that those taking the drugs actually had a slightly higher risk, of 3%, of experiencing heart attack, stroke or sudden death, compared with those who had never used ADHD medications; there was little difference, however, between those who used the drugs currently and those who had used them in the past but stopped.
Further, when the researchers looked at all serious heart events together, and also accounted for other factors that can affect heart disease, such as age, race, smoking and obesity, they found that ADHD drug users showed a lower risk of cardiac events overall than non-users. That may be because while the drugs were associated with a slightly higher risk of heart attack, they were linked to a slightly lower risk of stroke and sudden death.
Habel cautions that the findings shouldn’t be taken as a sign that ADHD medications can protect people from serious heart problems. In fact, she says there is evidence that people taking ADHD medications may be healthier in general — or at least try to take better care of their health — than those who don’t. People who take medications tend to be more concerned about their bodies and health and, therefore, may start out with a lower risk of developing heart problems, compared with people who don’t take regular medications.
“I don’t want the message to be that these drugs are completely safe,” she says. “I don’t think our study can really say that. What we can say is that we don’t think there is a substantial increase in risk of heart problems from these drugs.”
Along with the earlier results in children and young adults aged 2 to 24, the new study, published in the Journal of the American Medical Association, adds to the evidence that ADHD medications don’t adversely affect the heart.