By Jessica Ward Jones, MD, MPH Associate News Editor
Reviewed by John M. Grohol, Psy.D. on June 28, 2010 Omega-3 fatty acid supplements may be useful in treating major depression.
New research shows that when patients with major depression and no concurrent anxiety disorder were treated with omega-3 supplements, their symptoms were markedly reduced compared to patients treated with placebo.
Major depression affects five to 10 percent of the population. Symptoms include severely depressed mood, loss of interest in usual activities, loss of pleasure, and fatigue. Sufferers can also experience marked weight loss or gain, insomnia or excessive sleep, feelings of worthlessness or excessive guilt, and recurrent thoughts of suicide. Three to four percent of patients commit suicide.
Diagnosis of major depression is made after symptoms have been present for two weeks or more. Many therapies have proven helpful, including medication, different forms of therapy, electroconvulsive therapy (ECT) in severe cases, and exercise.
Other evidence has suggested that the Mediterranean diet, which is high in fish, nuts, fruits, vegetables, and whole grains, may help protect against developing depression. This type of diet is high in omega-3 fatty acids.
Omega-3 fatty acids are essential nutrients, that is, the human body cannot manufacture them and we must obtain them from our diet. They are found in high concentrations in fish, especially oily fish from cold waters, nuts, and seeds. Omega-3 fatty acids are important in brain, eye and nerve health. Supplements are available, most often fish oil, but vegetarians can get supplements derived from flax seed or algae.
A diet high in omega-3 fatty acids is thought to have a number of health benefits including cardiovascular benefits, immune benefits, or potentially even protection from certain types of cancer. Risks from taking high-dose supplements include potential for increased bleeding tendency.
While other studies have suggested that a diet high in omega-3 fatty acids is helpful in depression, some experts argue that dietary studies cannot be used as proof that supplement pills are useful. No large-scale trials have studied the use of omega-3 supplements in depression.
Dr. Francoise Lespérance from the Centre de Recherche du Cenre Hospitalier at the Université de Montréal along with colleagues from McGill University, Université Laval in Quebec City, and Queen’s University in Kingston, Ontario conducted the largest study ever done to assess whether supplementation with omega-3 fatty acids, as opposed to diet alone, might benefit patients with major depression.
The team recruited 432 adults who had been diagnosed with major depression. Forty percent of the patients were taking antidepressants at the beginning of the study. Half of the patients were randomly assigned to the group that was given the omega-3 supplement (1050 mg of eicosapentaenoic acid, or EPA and 150 mg of docosahexanoic acid, or DHA) and the other half were given a placebo. The placebo consisted of sunflower oil flavored with a small amount of fish oil, so that neither the patients nor the researchers knew which group had the placebo.
The participants were followed for eight weeks and evaluated using both a self-assessment inventory and a clinician rated scale.
Initially, only a mild but statistically insignificant difference was seen between the groups.
However, a large number of patients also had anxiety disorders. When the patients with depression who did not have anxiety were treated with the supplements, they had a marked improvement in depressive symptoms.
Before taking any medication or supplement, even an over-the-counter medication, talk to your physician. Do not stop taking any medication without consulting your physician.
These results are encouraging in that patients may now have another treatment for major depression. Omega-3 supplements have fewer side effects, and perhaps less stigma than some traditional antidepressants, and may be more acceptable to some individuals. Future research may help better define which patients are most likely to benefit from omega-3 supplements, how supplements interact with other medications, and what dosage would be optimal.
Source: The Journal of Clinical Psychiatry
