The randomised double-blind study, published in Biological Psychiatry, compared the effects of EPA, docosahexaenoic acid (DHA) or placebo on the prevention of interferon-alpha (IFN-a) induced depression that commonly occurs during treatment for chronic hepatitis C virus infection.
Led by Professor Carmine Pariante of King’s College London, the team found that a two-week supplementation with EPA before INF-a treatment significantly reduced depression incidence compared to those receiving DHA or placebo – with just one in ten of those given EPA suffering from inflammation-induced depression, while three out of ten given DHA or placebo had depression.
"Even a short course (two weeks) of a nutritional supplement containing one such omega-3 polyunsaturated fatty acid (EPA) reduced the rates of new-onset depression to 10%,” said Pariante.
In addition, both EPA and DHA were found to delay the onset of depression, and both supplements were well tolerated, with no serious side effects, said the team.
"These new data provide promising support for omega-3 fatty acids to prevent depression, complementing other studies where omega-3's were found to enhance antidepressant treatment," commented Dr John Krystal, editor of Biological Psychiatry.
Pariante and his team recruited 152 patients with hepatitis C to participate in the RCT, each of whom was randomised to receive two weeks supplementation with EPA (3.5 g/day), DHA (1.75 g/day), or placebo (high oleic oil).
“We chose 3.5 grams of EPA and 1.7 grams of DHA per day, because our previous studies conducted in Taiwan using PUFAs as antidepressants showed the effective EPA dose to be between 2.2 g/day and 4.4 g/day and the effective DHA dose to be between 1.2 g/day and 2.2 g/day,” said the team.
Following the two-weeks of randomised-double blinded supplementation, the patients received a standard 24-week course of interferon-alpha treatment for hepatitis C and were evaluated repeatedly for depression – which commonly occurs in around 30% of patients undergoing treatment.
The team found that treatment with EPA, but not DHA or placebo, decreased the incidence of interferon-alpha-induced depression in patients being treated for hepatitis C from around 30% to 10%.
However, both EPA and DHA significantly delayed the onset of IFN-induced depression – with EPA and DHA delaying average onset to 12.0 and 11.7 weeks respectively, versus 5.3 weeks for placebo.
“To our knowledge, this is the first study to demonstrate the beneficial effects of omega-3 fatty acids in the prevention of IFN-a-induced depression,” wrote the team. “The main finding is that EPA pretreatment significantly decreased the incidence of IFN-a-induced depression in HCV patients.”
Although further work is still needed and the findings must be replicated, the team said that their data indicate that omega-3 polyunsaturated fatty acids may be effective in preventing depression in groups of people at high-risk of depression because of increased inflammation.
Source: Biological Psychiatry
Volume 76, Issue 7, 1 October 2014, Pages 559–566, doi: 10.1016/j.biopsych.2014.01.008
“Omega-3 Fatty Acids in the Prevention of Interferon-Alpha-Induced Depression: Results from a Randomized, Controlled Trial”
Authors: Kuan-Pin Su, Hsueh-Chou Lai, et al