Antidepressants didn't get to be the third-most commonly prescribed medication in the United States for nothing. In fact, says a new study, the medications taken by more than 10% of American adults may be so ubiquitous because they are used to do so much.
Depression medication, a new study suggests, has become a "do something" drug for primary care physicians to offer when a patient's complaints may only be vaguely related to depression.
In a study reported in the Journal of the American Medical Assn. on Tuesday, researchers reported that close to three in 10 antidepressant prescriptions written between 2006 and 2015 by general practitioners in Quebec, Canada, were for conditions for which the medications have not been approved by the U.S. Food & Drug Administration.
Doctors treated insomnia and pain — both of which are closely linked to depression — with antidepressants. But they also prescribed antidepressants to treat migraines, menopausal symptoms such as hot flashes, attention deficit and hyperactivity disorders and digestive system disorders.
Anxiety disorders and panic disorders were also common reasons for physicians to prescribe an antidepressant. Those conditions pushed prescribing of antidepressants for reasons other than strict depression to 45%. But they, too, are widely seen as variants of depression, and a wide range of antidepressants have been found safe and effective in treatment of those conditions.
Over the decadelong study period, the percentage of antidepressant prescriptions that were written for treatment of depression fell continuously.
One upshot, said the authors, is that it's not enough for physicians to send a patient with generalized symptoms of distress off with an antidepressant prescription.
"The mere presence of an antidepressant prescription is a poor proxy for depression treatment," said the authors of the report, published Tuesday in JAMA.
Beyond that, the authors wrote, the findings suggest there is a need for more and better research on the safety and effectiveness of using antidepressants to treat conditions other than depression.
The study's design was simple: When 158 participating physicians noted in an electronic medical record that they were prescribing one of several classes of antidepressant, they got a pop-up query asking what "indication" — the medical term for the condition being treated — prompted the decision. Of 101,759 prescriptions written, 55.2% were for depressive disorders and 18.5% were for anxiety disorders. But insomnia, pain, panic disorder, fibromyalgia, migraine and obsessive-compulsive disorder prompted most of the rest. Conditions such as nicotine dependence, sexual dysfunction and urinary and digestive system disorders also accounted for a much smaller proportion of antidepressant prescriptions.
The new report updates older research that found that primary care providers were routinely prescribing antidepressants without any diagnosis at all. One 2011 study found that in the 12 years leading up to 2007, 56% of antidepressant prescriptions written by physicians other than psychiatrists came without a formal diagnosis of depression or anxiety disorder.
Columbia University psychiatrist Mark Olfson, one of the authors of that 2011 study, said the new data appear to reflect some progress and is somewhat reassuring. The prescribing decisions reflected in the new study frequently reflected good practices backed up by solid research, he said. As an example, Olfson said, the use of trazedone — an antidepressant that is sedating — is increasingly seen as a safer medication for insomnia than benzodiazepines, which can cause dependency and other unwanted side effects.
Many antidepressants have also been shown effective in blunting certain kinds of chronic pain, making them a safer bet for most patients than highly addictive opioid pain relievers or over-the-counter medications that can pose hazards for the heart or liver.
In some cases, there's a simple financial explanation for the fact that the FDA has not approved a specific antidepressant for treating a condition other than depression, said Olfson: It's a costly process to get the agency to approve a new indication for a drug, and the common physician practice of prescribing medications "off-label" is perfectly legal. In many cases, he noted, a drug's manufacturer did not want to undertake the expense and bother of seeking the agency's blessing.
"There's still a lot to be done to sharpen antidepressant prescribing," said Olfson. "But a lot of this [prescribing] is lined up with reasonable targets."
MORE IN SCIENCE