Antidepressants may increase your chances of developing type 2 diabetes, according to a new review of scientific findings.

Researchers from the University of Southampton warned clinicians on Tuesday to exercise care when prescribing antidepressants given the possibility of a causal link between mood medications and the disease. However, researchers cannot say for certain whether such medications — tricyclic, atypical, serotonin reuptake inhibitors, and monoamine oxidase inhibitors — may be blamed for a heightened rise in type 2 diabetes among study participants.

Across the Western world, usage of antidepressant medication has risen dramatically during the past decade. More than one in 10 Americans over the age of 12 now takes an antidepressant, a four-fold increase since 1988, according to a 2011 study by the U.S. Centers for Disease Control and Prevention. That same year, antidepressant usage rose 9.6 percent from the previous year — a five-fold increase during the past generation — to 46.7 million prescriptions in a country with some 63 million inhabitants. Researchers observed similar rates across the European continent.

In recent years, investigators have conducted a bevy of studies to ascertain whether antidepressants might be linked to type 2 diabetes, with findings varying depending on study methodology, medication types, and the size of the study population. In the review, the British researchers assessed 22 studies along with three previous systematic reviews examining the effects of these medications on diabetes risk — finding that people were indeed more likely to develop diabetes when taking antidepressants, with some equivocation. They warned that different classes of antidepressants may present varying risks, asserting that long-term prospective randomized control studies should be conducted.

Yet, the Southampton researchers identified “several plausible” reasons for an association between antidepressants and an increased risk of diabetes, including a link between several antidepressants and significant weight gain, which in turn would present an increased risk of type 2 diabetes. Other studies, however, found an association between antidepressants and diabetes even after removing the variable of weight gain.

Katherine Barnard, a health psychologist at the university, described the study. “Our research shows that when you take away all the classic risk factors of type 2 diabetes; weight gain, lifestyle et cetera, there is something about antidepressants that appears to be an independent risk factor,” she told reporters. “With 46 million prescriptions a year, this potential increased risk is worrying.”

Barnard advised clinicians to consider the risk of type 2 diabetes when prescribing antidepressants, until further notice.

Richard Holt, a professor of diabetes and endocrinology at the university, added that doctors should emphasize diabetes risk prevention when prescribing antidepressants to their patients.

"While depression is an important clinical problem and antidepressants are effective treatments for this debilitating condition, clinicians need to be aware of the potential risk of diabetes, particularly when using antidepressants in higher doses or for longer duration,” he said. “When prescribing antidepressants, doctors should be aware of this risk and take steps to monitor for diabetes and reduce that risk of diabetes through lifestyle modification."

Sources: Rubin RS, Yong M, Marrero DG, Peyrot M, Barrett-Connor EL, Elevated Depression Symptoms, Antidepressant Medicine Use, And Risk Of Developing Diabetes During The Diabetes Prevention Program. Diabetes Care. 2013.

Are Antidepressants Overprescribed? Yes. British Medical Journal. 2013.