Omega-3s Recommended as Adjunctive Therapy for Major Depression

September 25, 2019, Medscape

A clinical practice guideline from the International Society for Nutritional Psychiatry Research (ISNPR) recommends omega-3 polyunsaturated fatty acids (PUFAs) as adjunctive therapy for major depressive disorder (MDD).

The value of omega-3 PUFAs in depression is "overlooked," even though accumulating evidence supports it. This therapy "needs to be on the radar" of physicians, Kuan-Pin Su, MD, PhD, chief of the Department of General Psychiatry, China Medical University, Taichung, Taiwan, told Medscape Medical News.

Su, a founding member of the ISNPR and a strong proponent of "nutritional psychiatry," organized a subcommittee of the ISNPR and invited the top 10 most-cited authors in the use of omega-3 PUFAs for depression to review the literature and develop the practice guideline on appropriate prescribing of omega-3 fatty acids for MDD.

The consensus guideline was published online September 3 in Psychotherapy and Psychosomatics.

Prophylaxis, Maintenance

The guideline emphasizes the importance of accurate clinical diagnosis and measurement-based psychopathologic assessments in the therapeutic setting when recommending omega-3 PUFAs for depression.

The guideline notes that there is a growing body of evidence demonstrating the efficacy of n-3 PUFAs as an adjunctive treatment for MDD. The guideline authors also note that omega-3s are safe and effective for accelerating the effect of antidepressants at treatment initiation and for augmenting existing antidepressant therapy when efficacy is inadequate.

With respect to formulation and dosage, the guideline recommends pure eicosapentaenoic acid (EPA) or a combination of EPA and docosahexaenoic acid, with net EPA starting from at least 1 g/day up to 2 g/day for at least 8 weeks as adjunctive treatment. Importantly, the authors note that the quality of n-3 PUFAs may affect therapeutic activity.

They call for further research into personalizing the clinical application of n-3 PUFAs in subgroups of patients with MDD whose omega-3 index is low or who have high levels of inflammatory markers.

The panel acknowledges in the guideline that there is ongoing debate on the benefits of omega-3 PUFAs for MDD. Meta-analyses have shown "only small but statistically significant effects," the authors write.

They note that in three meta-analyses, the estimated effect sizes (standardized mean differences between n-3 PUFAs and placebo) ranged from 0.23 to 0.56, with wide confidence intervals (CIs).