Preventing depression with omega-3: A clinical trial

The Publication

A 2014 article published in the Biological Psychiatry journal showed that supplementation with specific omega-3s can significantly reduce the incidence of interferon-alpha-induced depression.

This study was a randomised, double blind, placebo-controlled trial that gave nutritional supplements to people  undergoing interferon-alpha therapy for chronic hepatitis C. This therapy has been linked to pro-inflammatory induced depression, and this trial was designed to investigate whether specific omega-3 fatty acid supplements  might reduce symptoms.

The participants were given  either eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), both of which are omega-3 fatty acids, or a placebo. The supplements were given for two weeks before the interferon-alpha treatment began which then lasted for 24 weeks. Depressive symptoms were measured at multiple time points during the trial.

The results showed that supplementation with EPA reduced the incidence of depression. This was not shown for DHA or the placebo, but another  interesting finding was that supplementation with both EPA and DHA decreased the onset of depression when compared to the placebo.

Professor Carmine Pariante, lead author from the Institute of Psychiatry, Psychology and Neuroscience at King’s College London, said:

“It is now established that increased inflammation plays a role in causing depression in at least a subgroup of patients. Our study shows that even a short course of a nutritional supplement containing one type of omega-3 fatty acid (EPA) reduces the rates of new-onset depression to 10%, as opposed to the rate of 30% we usually see in this group…...We believe that this nutritional intervention restores the natural protective anti-inflammatory capabilities of the body, and thus protects patients from new-onset depression when inflammation occurs.”

Our Response

These findings are hugely important as they provide yet more evidence to support the role that nutritional interventions can have in the prevention of mental illness.. We believe Omega-3 supplements should be carefully considered more frequently in instances where drug treatments may lead to inflammation that then causes  depressive symptoms.

There is a body of evidence supporting the theory that specific omega-3s, such as EPA, can have a significant role in the onset and treatment of various types of depression. In this study the nutritional intervention was shown to be both effective and also caused no adverse side-effects.