(This is the first of two articles exploring the possible adjunctive uses for omega-3 fatty acids in treating psychiatric disorders-Ed.)
Intrigued by preliminary research indicating that omega-3 polyunsaturated fatty acids found in fish, fish oil and flaxseed may ameliorate symptoms in bipolar disorder (BD), schizophrenia and other psychiatric disorders, investigators have launched a series of double-blind trials evaluating fatty acids as adjunctive treatment. This article will discuss studies on bipolar disorder.
Mid-year, a four-month, double-blind, placebo-controlled study comparing omega-3 fatty acids (9.6 g/day) versus placebo (olive oil) in 30 patients with bipolar disorder was described in Archives of General Psychiatry (Stoll et al., 1999). The eight co-authors concluded, "Omega-3 fatty acids were well-tolerated and improved the short-term course of illness in this preliminary study of patients with bipolar disorder."
Andrew Stoll, M.D., director of the Pharmacology Research Laboratory at McLean Hospital in Belmont, Mass., assistant professor of psychiatry at Harvard Medical School and lead researcher for the pilot study, said he and colleagues are ready to conduct a longer study, under a four-year grant from the National Institutes of Health. It involves two sites: Harvard Medical School, with Stoll as lead researcher, and Baylor College of Medicine with Lauren B. Marangell, M.D., director of the psychiatry department's clinical psychopharmacology and mood disorders research, as lead researcher.
"It will be a larger-scale study involving 120 patients, with a similar design, but we are going to control for concomitant medications much more tightly, we are going to control for baseline mood states, and we are going to mask the placebo with a fish taste," he said, adding that these were the main criticisms of the original study.
In the published preliminary study, the subjects-all outpatients-were men and women ages 18 to 65 who met DSM-IV criteria for bipolar disorder types I and II. Forty percent of the study cohort had rapid-cycling symptoms. To enter the study, patients had to have experienced at least one manic or hypomanic episode within the past year. However, they also had to be free of notable medical or psychiatric comorbidity. Patients who were on other medications at the beginning of the study were allowed to continue on them. Subjects received seven capsules bid for a total daily omega-3 fatty acid dosage of 6.2 g of eicosapentanoic acid (EPA) and 3.4 g of docosahexaenoic acid(Drug information on docosahexaenoic acid) (DHA). Patients randomized to placebo also received seven capsules bid.
The primary outcome measure related to the emergence or continuation of mood symptoms. Patients ended their participation in the study and treatment was considered to have failed if the mood symptoms emerged or continued beyond 30 days in patients who were not euthymic at baseline. Secondary outcome measures were the results of the Young Mania Rating Scale, Hamilton Rating Scale for Depression, Clinical Global Impression Scale and Global Assessment Scale ratings, taken before and after treatment.