A meta-analytic review of double-blind, placebo-controlled trials of antidepressant efficacy of omega-3 fatty acids.
OBJECTIVE
Evidence has indicated an association between depression and low dietary intake of omega-3 polyunsaturated fatty acids (PUFAs). However, clinical trials examining the therapeutic benefit of omega-3 PUFAs in depression showed inconsistent results. The goal of this study is to systematically evaluate the antidepressant efficacy of omega-3 PUFAs by using meta-analytic method.


METHODS
MEDLINE, Embase, and PsycINFO databases were searched from 1966 through August 2006 using the key words (depression OR depressive disorder OR mood disorder) AND (omega-3 OR EPA OR DHA OR poly-unsaturated fatty acid OR fish oil). The search was limited to literature in English and clinical trials.


METHODS
Ten double-blind, placebo-controlled studies in patients with mood disorders receiving omega-3 PUFAs with the treatment period lasting 4 weeks or longer were included.


METHODS
Effect size (ES) of each individual study was derived by computing the standardized mean difference. A random-effects model was used to pool the ESs of all included studies.


RESULTS
When pooling the results of 10 included studies (N = 329), we found a significant antidepressant effect of omega-3 PUFAs (ES = 0.61, p = .003). Likewise, omega-3 PUFAs significantly improved depression in patients with clearly defined depression (ES = 0.69, p = .002) or with bipolar disorder (ES = 0.69, p = .0009). The dosage of eicosapentaenoic acid (EPA) did not change the antidepressant efficacy significantly. However, significant heterogeneity among these studies and publication bias were noted.


CONCLUSIONS
Although our meta-analysis showed significant antidepressant efficacy of omega-3 PUFAs, it is still premature to validate this finding due to publication bias and heterogeneity. More large-scale, well-controlled trials are needed to find out the favorable target subjects, therapeutic dose of EPA, and the composition of omega-3 PUFAs in treating depression.
Department of Psychiatry, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
Pao-Yen
PY
Lin
Kuan-Pin
KP
Su
D000328:Adult; D001714:Bipolar Disorder / Q000188:drug therapy*; D003866:Depressive Disorder / Q000188:drug therapy*; D004311:Double-Blind Method; D015525:Fatty Acids, Omega-3 / Q000627:therapeutic use*; D006801:Humans; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome
D015525:Fatty Acids, Omega-3