Antidepressants may boost risk of type 2 diabetes

A study found that antidepressant drugs can boost the risk of getting type 2 diabetes. The report, scheduled to be presented at the 2006 meeting of the American Diabetes Association (ADA) in Washington, D.C., tested the effects of antidepressant drugs on a person's proclivity for getting diabetes. The study was lead by Richard Rubin, who is an associate professor of medicine and pediatrics at the Johns Hopkins University School of Medicine in Baltimore and the president-elect of health care and education for the ADA.

For years the debate on whether depression causes diabetes, or vice versa, has been unresolved. But this study was the first large one to examine the effect of antidepressants on people at high risk of type 2 diabetes. Some experts think the use of certain types of antidepressants known as SSRIs (such as Prozac and Paxil) could cut the risk of getting diabetes, while others are not so sure.

The report was based on a re-analysis of part of the Diabetes Prevention Program, a large-scale study in which researchers reported in 2002 that those at high risk for getting type 2 diabetes who lost excess weight and exercised were able to prevent the onset of diabetes much of the time. The researches evaluated the effect on 3,187 participants who were split into three groups. The groups were the lifestyle intervention group, the placebo group and the group given the diabetes drug metformin. At the beginning, 5.7 percent were on antidepressants, and during the study, about 13.5 percent were taking antidepressants.

Those in the placebo and lifestyle groups who were on antidepressants were found to have a two-to-three times greater risk of getting type 2 diabetes than those from the metformin group taking antidepressants. The team also found that it didn't matter what antidepressant one took, tricyclic antidepressant or SSRI, because the risk of getting diabetes was still found in both the placebo and lifestyle groups. As to why metformin seemed to protect against the risk, the team have no answer just yet.

The findings could have enormous public health implications. Approximately forty million people in the United States are pre-diabetic and many of these people could be on antidepressants as well. More research is needed and the team plans to conduct more studies in the coming year.