Wong said she expected “trends to be similar” in the United States, although she can’t be sure.
The results were published online Feb. 21 in BMJ.
The author of an accompanying journal editorial, Daniel Morales, pointed out that off-label use “has always happened.”
“Some off-label prescribing has strong evidence, but pharmaceutical companies may not apply for a license for a new indication because it is a complex and expensive process,” said Morales, a fellow in the school of medicine at the University of Dundee in Dundee, Scotland.
The bottom line is that “the strength of evidence for using an antidepressant for a particular patient or condition” is equally important whether the antidepressant is used “on” or “off” label, said Morales.
Dr. David Katz, director of the Yale University Prevention Research Center in New Haven, Conn., cautioned against painting off-label prescribing in a broadly negative light.
The practice “invites concern and caution, but does not necessarily indicate poor choices,” he explained.
“I have prescribed off-label many times myself, and generally it was because my patient needed me to get creative to figure out how to help them when the more obvious choices had failed for various reasons,” Katz said.
He agreed that because the regulatory approval process is so expensive, drug companies often stop after acquiring approval in one area of use.
“But to be clear,” he added, “a product might work just as intended (or) hoped, even if there is no multinational randomized trial in the thousands to prove it,” Katz added.
Wong and her team suggested more research is needed to examine the effectiveness of off-label antidepressant uses.
Also, “when evidence is lacking, we encourage physicians to prescribe conservatively or engage with their patients in a shared decision-making process to decide whether taking an antidepressant is the right choice for them,” Wong added.