ω-3 Fatty acids for major depressive disorder in adults: an abridged Cochrane review

Abstract

Objective To assess the effects of n-3 polyunsaturated fatty acids (n-3PUFAs; also known as ω-3 fatty acids) compared with comparator for major depressive disorder (MDD) in adults. Design Systematic review and meta-analyses. Data sources The Cochrane Depression, Anxiety and Neurosis Review Group's Specialised Registers (CCDANCTR) and International Trial Registries searched to May 2015. CINAHL searched to September 2013. Trial selection Inclusion criteria: a randomised controlled trial (RCT); that provided n-3PUFAs as an intervention; used a comparator; measured depressive symptomology as an outcome; and was conducted in adults with MDD. Outcomes Primary outcomes were depressive symptomology and adverse events. Results 20 trials encompassing 26 relevant studies were found. For n-3PUFAs versus placebo, n-3PUFA supplementation resulted in a small-to-modest benefit for depressive symptomology: SMD=−0.32 (95% CI −0.52 to −0.12; 25 studies, 1373 participants, very low-quality evidence), but this effect is unlikely to be clinically meaningful, is very imprecise and, based on funnel plot inspection, sensitivity analyses and comparison with large well-conducted trials, is likely to be biased. Considerable evidence of heterogeneity between studies was also found, and was not explained by subgroup or sensitivity analyses. Numbers of individuals experiencing adverse events were similar in intervention and placebo groups (OR=1.24, 95% CI 0.95 to 1.62; 19 studies, 1207 participants; very low-quality evidence). For n-3PUFAs versus antidepressants, no differences were found between treatments in depressive symptomology (MD=−0.70 (95% CI −5.88 to 4.48); 1 study, 40 participants, very low-quality evidence). Conclusions At present, we do not have sufficient evidence to determine the effects of n-3PUFAs as a treatment for MDD. Further research in the form of adequately powered RCTs is needed.

N-3 polyunsaturated fatty acids promote astrocyte differentiation and neurotrophin production independent of cAMP in patient-derived neural stem cells

“…N-3 PUFAs play fundamental roles in brain structure and function. Accumulating evidence has implicated deficiency of n-3 PUFA (EPA and DHA) in the etiology of depression and n-3 PUFA in the treatment of MDD [13, 15]. Multiple mechanisms might underlie the protective/therapeutic effect of n-3 PUFAs on MDD [13–17].…”

Bioactive lipids as modulators of immunity, inflammation and emotions

“…The effects of EPA and more importantly of DHA (the most abundant v-3 PUFA in the brain) on brain plasticity might also provide a possible mechanism, presumably through their metabolites such as SPMs, or the DHA eCB-like metabolite N-docosahexanoylethanolamine (DHEA, also known as synaptamide) [56]. However, a recent clinical trial failed to provide sufficient evidence to determine the effects of v-3 PUFAs as a treatment for major depressive disorder in adults, suggesting that future research in the form of adequately powered randomized controlled trials is needed [57].…”

Systematic Review of Meta-Analyses: Exercise Effects on Depression in Children and Adolescents

“…There was no indication that one of the treatments was more or less efficacious, with the exceptions of interpersonal psychotherapy (which was more effective; d = 0.20) and nondirective supportive treatment (which was less effective than the other treatments; d = −0.13) (8). New avenues to treat major depressive disorders in adults are offered such as ketamine (10), nutritional interventions such as thiamine (11), and omega-3-polyunsaturated fatty acids (12)(13)(14)(15) as well as neuromodulation (16).…”