Black-box warnings about dangers of ADHD drugs confusing, say researchers

Black-box warnings about the dangers of attention-deficit hyperactivity disorder (ADHD) medications are confusing and could have serious consequences for the risk of youth suicide, according to researchers at the Institut universitaire en santé mentale de Montréal (CIUSSS de l'Est-de-l'Île-de-Montréal) and the University of Montreal, whose correspondence has just been published in the most recent issue of the journal The Lancet Psychiatry.

"Health Canada has issued a series of black-box warnings about the suicidal potential of ADHD medications. However, these warnings have failed to take into account epidemiological studies showing the opposite, that increased use of this medication has been associated with reduced suicide risk in adolescents," says Dr. Alain Lesage, psychiatrist and researcher at the Institut universitaire en santé mentale de Montréal (CIUSSS de l'Est-de-l'Île-de-Montréal) and one of study's authors.

In the past decade, the medical treatment of ADHD increased three-fold in Quebec, reaching 9% of boys aged 10 years and 4% of boys aged 15 years. However, suicide rates in Quebec's adolescents decreased by nearly 50% during that period among 15-19 year olds, which contradicts the warnings issued by Health Canada.

"Clearly, the increased use of ADHD drugs indicates that they might actually reduce rather than augment the risk of suicide," says Edouard Kouassi, pharmacist and researcher at the Institut universitaire en santé mentale de Montréal (CIUSSS de l'Est-de-l'Île-de-Montréal) and co-author of the study.

How can this decrease be explained clinically?
"Randomized controlled trials have shown ADHD medication to alleviate the usual symptoms of hyperactivity and attention deficit. It has also been associated with improvements in school performance, better self-esteem, and reductions in conduct disorders, drug abuse, and pregnancies in girls. In fact, these disorders or precarious social situations are especially associated with increased risk of suicide, not the actual taking of these drugs, which, on the contrary, may prevent suicide," say the authors.

Indeed, Health Canada's black-box warming may contribute to reducing prescriptions because of parents' fears about their children's health, while these medications may actually protect them. "The silence from the Public Health Agency of Canada (PHAC) is especially worrying in a context in which it has been called on to prepare a national suicide prevention strategy for the government of Canada under Bill C-300. We wrote this correspondence hoping to sound the alarm about the warnings published by Quebec's health authorities, as elsewhere in Canada, which might lead to a decrease in this effective medical treatment," they conclude.