Antidepressants associated with decreased mortality rates in patients with diabetes and depression

In patients with diabetes and depression, antidepressant use may be associated with a lower risk for death, a recent study found.

Researchers in Taiwan performed a retrospective cohort study using a national database to examine antidepressant use and mortality in patients with both diabetes and depression. Patients with newly diagnosed diabetes and depression were identified starting in 2000 and were followed for mortality until 2013. Categories of antidepressants were divided into three groups by cumulative dose exposure, and risk for death was determined by comparing the highest-dose group to the lowest-dose group. The study's main outcome measure was an association between mortality and antidepressant use, adjusted for cumulative dosing. Results were published by the Journal of Clinical Endocrinology & Metabolism on July 2.

Overall, 53,412 patients with both diabetes and depression were identified, 50,532 who were taking antidepressants and 2,880 who were not. Those in the latter group were more likely to be men and to be elderly. Use of antidepressants was associated with a significantly reduced risk for death, and after adjustment, total mortality decreased as total cumulative antidepressant dose increased, with a hazard ratio (HR) of 0.65 (95% CI, 0.59 to 0.71) for those in the highest-dose group. Different categories of antidepressants appeared to yield different benefits, with HRs of 0.63 (95% CI, 0.56 to 0.71) for selective serotonin reuptake inhibitors, 0.58 (95% CI, 0.44 to 0.78) for serotonin-norepinephrine reuptake inhibitors, 0.20 (95% CI, 0.07 to 0.63) for norepinephrine-dopamine reuptake inhibitors, 0.60 (95% CI, 0.45 to 0.82) for mirtazapine, 0.73 (95% CI, 0.54 to 0.97) for tricyclic/tetracyclic antidepressants, and 0.52 (95% CI, 0.29 to 0.91) for trazodone. One drug, moclobemide, a reversible inhibitor of monoamine oxidase A that is not FDA approved, was associated with increased mortality (HR, 1.48; 95% CI, 1.09 to 1.99).

The authors noted that they did not have information on patients' causes of death, that a diagnosis of depression may not have been valid in all cases, that comorbid conditions such as smoking and obesity were not included, and that the results may not be generalizable to other populations. They concluded that their data identify an inverse association between antidepressant use and mortality in patients with diabetes and comorbid depression and that higher doses seemed to yield greater benefit. Their results provide “further rationale for the screening and treating of depression in persons who have [diabetes mellitus],” the authors wrote.