Fish Oil and Depression

In addition to its heart-related health benefits, fish oil, and more importantly its major nutritional component omega-3 fatty acid, may also be useful in treating another set of diseases. Namely, depression and anxiety disorders. However, the evidence is still not clear on this point and anecdotal stories run rampant, becoming a sort of "truth" that is passed along. So what do we know about fish oil and depression, and how can it help you? As far as scientific studies go there are several that show contradictory information, and one that concluded positive results in treating bipolar disorder. In addition, several users have reported anecdotal success with fish oil and depression. In this article we'll take a look at the research and see where it stands.

There have been a few studies on the effect of fish oil on bipolar disorder; one examined the effects of omega-3 fatty acids on 30 bipolar patients over the course of four months. The patients showed improvement when supplemented with omega-3.

Omega-3 is the principle fatty acid found in fish oil, although there are two types in this supplement: EPA and DHA. DHA is the most beneficial, nutritionally, and counteracts the negative effects of the omega-6 fatty acids so prevalent in the typical Western diet (think: hamburgers and french fries).

However, in studies involving bipolar disorder, such as the above, it is the EPA acid that is the active ingredient. EPA is quite abundant in fish oil. But does it affect plain-old, vanilla depression?

The research is unclear on this point.

In one study, 77 depression patients began receiving randomly either fish oil or olive oil (the placebo) supplement in addition to treatment they were already using. There was no improvement seen between the two oils. However, another study concluded the opposite.

In a study published in the Archives of General Psychiatry in 2002, 70 sufferers of depression were given various amounts of fish oil and ended up with significantly reduced symptoms as compared to the placebo group. Interestingly, the patients who received only 1g of fish oil had a much larger improvement in symptoms than those who had a larger dose. Something to consider if you are going to try this treatment. So we have a few contradictory scientific studies. But what about users "in the field?" What does the anecdotal evidence show?

On the popular, one user found success with .1g daily for his depression. That's one tenth of one gram. Another had been taking about 8g per day for several years, and while his symptoms slowed in the beginning, he thought he may have been developing a tolerance as it seemed to be working less well over time. Could this be confirmation of the above study? That lesser amounts of fish oil work better for depression than more?

And where does this leave us, then? Unfortunately, we still don't have an answer. As you can see, omega-3 acids are beneficial to bipolar patients according to one study, but possibly not as much so for depression. We'll have to call this one "inconclusive" at this point. While some depression sufferers obviously have seen some relief from fish oil, there could be other factors involved as anecdotal stories just don't carry a lot of weight by definition. However, as depression can be such a subjective disease and different medication works differently for different people, I recommend giving fish oil a try for your depression as long as you ask your doctor first. And keep in mind the possibility that less may work better than more.


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Prostaglandins Leukot Essent Fatty Acids. 2005 Mar;72(3):211-8

Arch Gen Psychiatry 2002 Oct; 59:913-9