Omega-3 Fatty Acids and Mood Disorders

Another interesting article from the American Journal of Psychiatry, titled

"Omega-3 Fatty Acids and Mood Disorders"

Here are the main points; below that there's a summary of the article.


Objective: This article is an overview of epidemiological and treatment studies suggesting that deficits in dietary-based omega-3 polyunsaturated fatty acids may make an etiological contribution to mood disorders and that supplementation with omega-3 fatty acids may provide a therapeutic strategy.

Method: Relevant published studies are detailed and considered.

Results: Several epidemiological studies suggest covariation between seafood consumption and rates of mood disorders. Biological marker studies indicate deficits in omega-3 fatty acids in people with depressive disorders, while several treatment studies indicate therapeutic benefits from omega-3 supplementation. A similar contribution of omega-3 fatty acids to coronary artery disease may explain the well-described links between coronary artery disease and depression.

Conclusions: Deficits in omega-3 fatty acids have been identified as a contributing factor to mood disorders and offer a potential rational treatment approach. This review identifies a number of hypotheses and studies for consideration. In particular, the authors argue for studies clarifying the efficacy of omega-3 supplementation for unipolar and bipolar depressive disorders, both as individual and augmentation treatment strategies, and for studies pursuing which omega-3 fatty acid, eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), is likely to provide the greatest benefit.
(Am J Psychiatry 163:6, June 2006)

I learned a few things from this paper: first, the omega-3 fatty acids can be either marine-based or from plants.
The rapid growth in population has been associated with a change in diet, resulting in a decrease in omega-3 while the uptake of omega-6 (e.g. from vegetable oils) has increased. Some authors suggest that there's a connection between the depression-rate and other neurological disorders and the increase of the omega-6 fatty acids; there's a possible link between fish consumption and mood disorders. Both Iceland and Japan, which both have high consumption rates of fish, have low rates of "seasonal affective disorders". As the consumption rate of fish declines (and the consumption of 'Western' food rises), the rates of seasonal affective disorders increases, even when they receive more winter sunlight. Furthermore, the "likelihood of having depressive symptoms was significantly higher among infrequent fish consumers than among frequent consumers." Some research also opposes these findings, but there's a general tendency to support the previously mentioned claims. Other research state that this is especially so with women. But in short, 5 out of 6 researches find that there's a correlation between fish consumption (omega-3 intake) and mood disorders.
During pregnancy the fetus accumulates more DHA (primary component of omega-3) than the intake of the mother, and after the birth the depletion of the omega-3 acids continues by breast-feeding. This contributes to the risk for depression around the time of birth. So feed your wife some fish during pregnancy (finally a reason to be happy someone eats dead animals);

• it's safe
  
• it may have "additional benefits for the infant’s neurodevelopment"
  

Then there's a lot of biological mumbo-jumbo, which I don't fully understand, but which still support the previous claims. Some possible mechanisms are presented, to continue to the treatment studies. Bipolar/depressed/borderline patients which took omega-3 had in general greater symptom reduction. On the other hand, there are some experiments which don't reproduce this effect, but again, in general, the results support the previous idea.

Interesting stuff.