medsAntidepressants are among the most commonly prescribed drugs in the United States. It would be safe to assume, then, that depression is one of the most common ailments. While that may certainly seem true, new research says that many doctors are actually prescribing antidepressants for patients suffering from conditions other than depression.

Antidepressant prescriptions are actually on the rise throughout the world, but in the United States, numbers increased nearly 400 percent between study periods 1988-1994 and 2005-2008. As a matter of fact, the United States Centers for Disease Control and Prevention (CDC) intimates that at least 11 percent of American teens and adults presently take antidepressants.

But, again, not all of these prescriptions are intended to treat depression. The study—which has been published in the Journal of the American Medical Association—that approximately three out of every ten prescriptions written [by general health practitioners in Quebec, Canada] were for conditions not approved by the US Food and Drug Administration.

Basically, doctors are using antidepressants to treat other conditions that are often linked with depression. This might include things like insomnia, ADHD, and anxiety but some doctors have prescribed antidepressants to treat migraines, digestion issues, and even menopausal symptoms.

While this may seem counter-intuitive it is, apparently, quite a common practice.

“I’ve always written these are not necessarily best called antidepressants,” explains Brown University professor Peter Kramer. While not involved with this study, he goes on to say, “They are active in the nervous system, but whether they reverse depression or they intervene against certain kinds of injuries against nerve cells in some general way that isn’t targeting depression, that seems to be an open question.”

Still, researchers currently believe that this uncertainty surrounding antidepressant use—and how they might impact non-depression conditions—should be regarded as important.

“The thing that’s of concern here is that when prescribing for conditions other than depression, often these are for indications such as fibromyalgia and migraine where it’s unknown whether the drug is going to be effective, because it’s never been studied,” warns lead study author Robyn Tamblyn, from the University of Montreal. She advises that too many doctors may be “prescribing in the dark,” contributing this trend, and that could have serious repercussions until more research can be done to expand antidepressant classification. While the drugs are not necessarily dangerous, there may be side effects or other concerns we simply no nothing about at this time.

Get Analysts' Upgrades and Downgrades Daily - Enter your email address below to receive a concise daily summary of analysts' upgrades, downgrades and new coverage with MarketBeat.com's FREE daily email newsletter.