Attention-deficit hyperactivity disorder (ADHD) medications already get a bad rap — but do they increase the risk of teen suicide?

If you’re looking at the recent black-box warnings issued for ADHD meds in Canada, you might be inclined to say yes. In March 2015, Health Canada stated there was a need for stronger, clearer warnings in prescription drug information based on "information that suggested these risks may apply to all other ADHD drugs." It also stated there was little evidence to establish that these drugs increase the risk of suicide, "but it is possible that they may contribute to the risk."

These warnings confuse researchers from the University of Montreal, who have a new correspondence on the matter in The Lancet Psychiatry. The warnings don't take into account all available evidence, they said, least of all the epidemiological studies that have arrived at a different conclusion.

Researchers believe Health Canada failed to take advantage of the chronic disease surveillance systems available under the Public Health Agency of Canada and the Quebec Public Health Agency, both in place to monitor teen suicide rates. The prescription of ADHD meds have increased three-fold in Quebec, researchers cited, so if ADHD meds increase the risk of suicide, then it would be associated with an increased risk of suicide among children and adolescents at a population level. Instead, they found suicide rates among this group have actually decreased by nearly 50 percent.

This suggests, then, that ADHD meds may be associated with a reduced risk of teen suicide.

"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," the authors said, according to a press release. "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."

Researchers said Health Canada should be concerned with its latest warnings because it might lead to a decrease in what’s an otherwise effective medication; they've seen something similar happen with antidepressants. Though, perhaps this concern isn’t limited to Health Canada.

"Although Health Canada’s decision is worrying, so too is the silence from the Public Health Agency of Canada (PHAC) and the Chief Medical Officer, who, in theory, are responsible for monitoring suicides, the silent epidemic that killed 3890 Canadians in 2009 — about ten adults every day and two adolescents every 3 days in Canada," researchers wrote.

In the United States, teen suicide is no less prevalent. The most recent data from the Centers for Disease Control and Prevention shows suicide is the third-leading cause of death among people ages 10 to 24, though studies show rates nearly double in rural areas. Risk factors in general may vary, but having the necessary information makes a difference.

Researchers hope their correspondence will "sound the alarm" about black-box warnings and pave the way toward effective medical treatment.

Source: Lesage A, Renaud J, Kouassi E, Vincent P. Canadian ADHD black-box warnings. The Lancet Psychiatry. 2015.