Antidepressant use tied to increased diabetes risk

People who use antidepressants for the long term may be more likely to develop type 2 diabetes than non-users - including other individuals with severe depression, two new studies suggest.

The findings, reported in the journal Diabetes Care, add to evidence linking antidepressant use to a modest elevation in type 2 diabetes risk.

They do not, however, prove that the medications are the cause, researchers say.

It's possible that antidepressant users have other characteristics that raise their odds of developing diabetes, according to Dr. Mika Kivimaki of the University College London in the UK, the lead researcher on one of the studies.

In addition, he told Reuters Health in an email, antidepressant users may see doctors more often than non-users do - which, in turn, could increase their likelihood of being diagnosed with diabetes or other medical conditions.

"I would interpret these findings cautiously and not draw firm conclusions yet," Kivimaki said.

For their study, he and his colleagues used data on more than 150,000 Finnish adults followed for an average of five years. During that time, 851 were newly diagnosed with type 2 diabetes.

At the outset, there were 9,197 individuals who were considered longer term users of antidepressants - having been on the medications for more than six months. Overall, the researchers found, these men and women were more likely to develop diabetes during the study period, with the odds climbing in tandem with the length of use.

Among study participants who had not used the medications, 1.1 percent were diagnosed with diabetes over five years. That compared with 1.7 percent among individuals who had taken between 200 and 400 daily doses of an antidepressant, and 2.3 percent among those who had taken 400 or more daily doses.

One question about the association between antidepressants and diabetes has been whether the medications are just serving as a marker for more-severe depression: severe depression, or the generally poorer health and lifestyle that may come with it, could help explain the connection to diabetes risk.

But when Kivimaki's team looked only at participants considered to have severe depression, antidepressant users were two to three times more likely than non-users to be diagnosed with diabetes. That was with rates of chronic physical health conditions, like high blood pressure, heart disease and cancer, taken into account.

Of 159 people who had severe depression and had taken at least 200 doses of an antidepressant, 58 developed diabetes. That compared with 12 of 69 men and women who had severe depression but had taken fewer doses, or no medication at all.

In the second study, researchers led by Dr. Richard R. Rubin of Johns Hopkins University in Baltimore looked at data on more than 3,200 U.S. adults who were enrolled in a clinical trial on type 2 diabetes prevention.