The term "antidepressant" is increasingly becoming a misnomer, suggests new research published Tuesday in the Journal of the American Medical Association.

The researchers, led by Professor Jenna Wong of McGill University in Montreal, Canada, examined the prescription records of patients who visited select physicians in the province of Quebec from 2006 to 2015, specifically looking at those who were given antidepressants. Out of 100,000 such prescriptions, Wong’s team found that only 55 percent were indicated for the purpose of actually treating depression. The remaining 45 percent were intended as treatments for anxiety disorders, pain, and insomnia, and many other conditions. And 30 percent of the prescriptions fit the criteria of off-label use, meaning they were given out under circumstances never officially approved by regulatory agencies such as the Food and Drug Administration (FDA).

"I wasn't surprised by the indications themselves, but I was surprised by the extent,” Wong told Medical Daily.

The Wild West of Medicine

Wong and her team embarked on their study to address a particular research gap. While other studies have found similarly large rates of off-label prescribing, including in the United States, few if any were able to directly look at the original prescription records created by doctors themselves. Mcgill University, however, has long maintained an electronic database that allows Quebec physicians to effortlessly keep track of their patients’ prescriptions and medical records, the Medical Office for the Twenty First Century, or MOXXI, system. Though only about a third of doctors and patients volunteered their records to be used for later research, the data provided Wong’s team with a more reliable means of measuring off-label use.

Nefarious as it sounds, though, there’s nothing inherently wrong or illegal about off-label use. The drugs we take can have a variety of effects on our bodies, and there is a countless number of medicines that were designed, tested, and prescribed for one condition but were later found to help deal with another. Some older medications are even now routinely prescribed for conditions they never received clinical testing for, like the epilepsy drug gabapentin, which is used to treat neuropathic pain.

Agencies like the FDA have long respected the ability of doctors to judge their patients’ needs and to prescribe drugs off-label when called for, but have drawn the line at pharmaceutical companies directly marketing their products to consumers and doctors for conditions that they weren’t approved for. Regardless, Wong says, these companies have often managed to find ways to market and promote their drugs for unintended uses, and that in turn has influenced doctors to prescribe more. "Doctors may also think the newer antidepressants on the market are safer to use for other conditions as well," she added.

The problem with off-label prescribing is that there’s a lack of any good evidence for these uses in many situations. Academic journals have given the green light to intrepid scientists wanting to test out already available drugs for new conditions, but relatively few have the funding and resources needed to take them up on the offer. Likewise, pharmaceutical companies rarely want to go through the expensive process of seeking FDA approval for a new indication. So while off-label prescribing is rampant, it often isn't medically sound, Wong said. That doesn’t mean these drugs are necessarily worthless or dangerous to patients, it just means that we really have no idea whether they are or aren’t.

Off-label prescribing comes with another insidious problem, particularly in the case of antidepressants. Researchers and policymakers have relied, at least in part, on rates of antidepressant use to measure how many people are suffering from depression, often to argue that people are getting more depressed than ever. But while there has been a noticeable rise in the number of people receiving a diagnosis of major depression, research by Wong and others indicates that we simply can’t use antidepressant use as a reliable measure of an otherwise very real danger to our mental health. And any future study that does try to do so will have to account for off-label use, Wong said.

The current study found that around 6 percent of all prescriptions doled out were antidepressants, a figure lower than the 11 percent rate for Americans, according to the Centers for Disease Control and Prevention. The rates of off-label antidepressant use in the study ranged from 47 percent for anxiety disorders — the second-most prescribed condition following depression at 19 percent — to 97 percent for insomnia, the third-most prescribed condition at 10 percent.

Rather than demonizing the practice of off-label prescribing entirely, Wong and her colleagues hope their findings simply highlight how common it actually is. “I think a lot of patients aren’t aware that the antidepressants they’re being prescribed for a particular problem sometimes have little sound scientific evidence behind them, and the same could be said for many doctors,” said Wong. And because pharmaceutical companies are often unwilling to foot the bill for off-label research, she hopes her research can motivate policymakers in the government to publicly fund these crucial studies.

Source: Wong J, Motulsky A, Eguale T, et al. Treatment Indications for Antidepressants Prescribed in Primary Care in Quebec, Canada, 2006-2015. JAMA. 2015. JAMA. 2015.