Ethyl-EPA may be useful in bipolar depression

Patients with bipolar depression receiving adjunctive ethyl-eicosapentaenoic acid (EPA) achieved better clinical outcomes than those receiving placebo in a recent UK study.The 12-week double-blind study involved 75 patients aged 18 to 70 years with a DSM-IV diagnosis of bipolar disorder I or II and a score of at least 10 on the 17-item Hamilton Rating Scale for Depression (HRSD-17).Following baseline assessment using the HRSD, the Young Mania Rating Scale (YMRS) and the Clinical Global Impression Scale (CGI), patients were randomly assigned to ethyl-EPA 1g/day, ethyl-EPA 2g/day or placebo. Patients were included in the study only if their existing psychotropic medication had remained unchanged for eight weeks prior to baseline assessment. Patients who were medication-free were required to have been so for the previous eight weeks.The study medication comprised capsules containing ethyl-EPA 500mg or liquid paraffin 500mg. In all cases patients were required to take two capsules twice daily with food. The primary outcome measure used in the study was change in HRSD score from baseline to the study endpoint. Secondary endpoints included change in YRMS and CGI scores from baseline to study endpoint.The researchers found no differences between the two ethyl-EPA groups in terms of the primary and secondary outcome measures hence the two groups were combined for the purposes of data analysis. The mean HRSD score at week 12 was significantly lower in the ethyl-EPA groups compared with the placebo group (3.3 points, p=0.03). Similarly the mean CGI score at week 12 was significantly lower in the ethyl-EPA groups compared with the placebo group (0.79 points, p=0.04). The mean YMRS score at week 12 was 3.3 points lower in the ethyl-EPA groups compared with the placebo group. However, this difference was not significant (p=0.17).The most frequently reported side effects were loose stools and gastrointestinal discomfort. There were no differences between the groups in terms of the occurrence of such effects.The researchers state that the precise mechanism of action of ethyl-EPA in improving bipolar depression is unknown.The researchers conclude that adjunctive ethyl-EPA treatment of bipolar depression appears to have antidepressant effects and minimal propensity to induce mania. In addition, the treatment is safe and well tolerated.They add that as ethyl-EPA is a naturally occurring compound it may prove more acceptable to patients than other pharmacological interventions.Reference...