Fear of Stimulant Therapy for Children and Adolescents with Attention-Deficit/Hyperactivity Disorder

To The Editor:

In the June/July issue of the journal, Daalsgard et al. (2014) reported finding that stimulant treatment increased the risk of cardiovascular disease in children and adolescents with attention-deficit/hyperactivity disorder (ADHD). This finding is at odds with studies of children and adolescents with ADHD including >5,000,000 patient years of observation in which stimulants have not been found to increase the risk of cardiovascular disease.

The greatest problem with this article is the authors' flawed assumption that an emergency room (ER) or physician contact for cardiovascular symptoms (i.e., a cardiovascular “event”) is comparable to having cardiovascular “disease.” This assumption is so deeply imbedded into their work that the authors use the terms cardiovascular “event” and cardiovascular “disease” interchangeably. However, they provide no data (e.g., chart reviews) substantiating the validity of this assumed relationship.

In truth, these cardiovascular “events” are poor predictors of cardiovascular disease. I coauthored a similar study (Winterstein et al. 2007) in which we identified 1071 such cardiovascular “events” (i.e., ER or physician office visits resulting in cardiovascular diagnosis). We found that very few of these “events” (∼2%) were the result of serious cardiovascular disease. This included five cardiovascular deaths – all in children never exposed to stimulants.

The authors identified five “serious” cardiovascular events among children with ADHD, including one child who had a myocardial infarction. All five of these serious cardiovascular events also occurred in children never exposed to stimulants; a highly relevant finding. However, although the authors noted their occurrence, they chose to disregard the significance of these events and even went so far as to remove all of them from their data analyses.

The fact that the authors excluded such critical data is one of many flaws that discredit their claim to have discovered an increased risk of cardiovascular disease associated with stimulant use.

Unfortunately, the general media are always drawn to such alarming claims, and this article generated many frightening headlines such as “Stimulants double the risk of cardiovascular disease” (a “fact” that was even reported on Dr. Oz's highly influential health blog).

Untreated childhood ADHD can cause devastating psychological and emotional damage. How do we calculate the risk of harm done when needlessly frightened parents decide against treating their children struggling with ADHD?