Mortality
Can Stimulants Be Life-Threatening?
Several years ago, both Health Canada and the US Food and Drug Agency reviewed the studies of sudden unexplained death (SUD) among ADHD patients taking stimulants and found no convincing connection between use of stimulants and elevated rates of SUD.
About 1 in 27,000 people in the US will experience SUD each year. That means that, on average, of every 2 million people, 74 will die suddenly each year for no apparent reason – whether they are taking stimulants or not. So if 74 of the 2 million people taking stimulants experience SUD, that would not be evidence that stimulants cause SUD. The number of deaths each year of people taking stimulants would have to be statistically larger to be cause for concern, and it is not known to be.
Still, in almost 50% of the of deaths of people taking stimulants, it turns out that there was a pre-existing heart problem, often not previously recognized, or a family history of unexplained death at an early age. To me that means that people who have heart problems or have a blood relative who died young for no apparent reason should be wary of taking stimulants, which are known to increase the heart rate and blood pressure in some people. If stimulants are strongly indicated, it would be prudent to get a consultation from a cardiologist before deciding to start them.
Early in the summer of 2009, a study published in the American Journal of Psychiatry reported that children who experienced SUD were more likely to have been taking stimulants than children who were not. While provocative, this doesn’t tell whether stimulants caused the SUD. Imagine a study that showed that men who died of a heart attack were much more likely to have had brown lawns than men who didn’t have a heart attack. Men living in areas where the summer sun is excessively hot have more heart attacks – and brown lawns – but the brown lawns do not cause the heart attacks. Similarly, because stimulants were associated in the study with SUD, it is tempting to conclude that they caused the deaths. An association like this can be an important clue or a coincidence or a very misleading clue (as it is with the brown lawns). Associations should not be used as the basis for conclusions.
The Editors of the American Journal of Psychiatry, which published this study, noted that “these data suggesting a link between sudden unexplained death and a medication commonly used to treat ADHD cannot be dismissed because the sympathomimetic activity of stimulants provides biological plausibility for cardiovascular effects (3). However, it is equally clear that 1) sudden unexplained death is a rare event, 2) this is only the first such study, 3) it relies on small numbers, and 4) it is not possible to quantify the risk beyond estimating that it is very small. A full estimate of the risk-benefit ratio of ADHD treatment cannot be properly conducted at the population level because sudden unexplained death is so rare and we lack controlled long-term data on the effectiveness of these medications for reducing the risk for other adverse health outcomes, such as accidents, medical hospitalizations, unsafe sex practices, antisocial behavior, and substance abuse, which have been associated with ADHD.”
Hopefully more research will bring greater clarity regarding the possible role of stimulants in SUD some time soon. Still, if there is a chance of sudden cardiac death from stimulants, what can be done to minimize it? The risk of SUD in pediatric patients taking stimulants is probably comparable to the risk of SUD among students taking part in athletic activities. While this risk is low, it may be reduced further by the doctor…
- taking a careful medical history of the patient and his or her biological family especially with regard to heart problems, brain disorders, fainting, seizures, and SUD of a blood relative at an early age
- doing a physical exam at baseline and, if physical problems arise later, during treatment
- asking the patient to notify him or her if cardiac symptoms such as unexplained chest pain, fainting, and palpitations appear
- where there is a family history of heart problems early in life, it would be reasonable to obtain an EKG and a cardiac consultation since there may be a heart problem that is not obvious.
In many European countries, EKG screening for all student athletes participating in organized sports is mandatory. Studies in Japan have shown that EKG’s are more sensitive to cardiac abnormalities than are a medical history and physical exam, and universal screening of school children for cardiovascular disease has been mandatory since 1973.
