The findings, reported in the Journal of the American Medical Association for October 21, run contrary to prior studies showing that certain omega-3 supplements augment the efficacy of standard antidepressant therapy, Dr. Robert M. Carney, from Washington University School of Medicine, St. Louis, and colleagues point out.
“At the present time, there is no evidence that omega-3, at least the type and dosage of omega-3 used in this study, improves the effectiveness of antidepressants in patients with heart disease,” Dr. Carney noted in email to Reuters Health.
After a 2-week run-in period, the investigators had 122 patients with major depression and coronary heart disease (CHD) start sertraline at a dose of 50 mg/day, at which point patients were randomized to one of two arms: treatment with 2 g/day of omega-3 acid ethyl esters (930 mg EPA and 750 mg DHA), or corn oil placebo capsules.
During the study, which lasted for 10 weeks, medication adherence was high in both groups (97% or more), the researchers report.
Dr. Carney said that while patients in both groups responded to treatment, “there was no difference in improvement between those who got omega-3 and those who received the corn oil placebo.”
In both groups, estimated weekly Beck Depression Inventory (BDI-II) scores showed that depressive symptoms improved over time at comparable rates, and the placebo and omega-3 groups did not differ at 10 weeks with regard to depression or anxiety.
Moreover, there was no significant difference in the rate of remission between the placebo group and the omega-3 group (27.4% vs 28.3%; respectively, odds ratio 0.96) or response to treatment (49.0% vs 47.7%; respectively, odds ratio 1.06).
“We expected depression symptoms in patients taking both sertraline and omega-3 to improve more than in those taking the antidepressant drug and the corn oil placebo,” Dr. Carney said.
The findings are “disappointing,” he added, “in light of the fact that depression is a significant risk factor for cardiac mortality and we are in need of more effective treatments for depression in these patients.”
“Whether higher doses of omega-3 or sertraline, a different ratio of EPA to DHA, longer treatment, or omega-3 monotherapy can improve depression in patients with CHD remains to be determined,” Dr. Carney and colleagues note in their report.