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Omega-3 fatty acids for depression in adults

Overview of attention for article published in Cochrane database of systematic reviews, November 2015
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  • In the top 5% of all research outputs scored by Altmetric
  • High Attention Score compared to outputs of the same age (99th percentile)
  • High Attention Score compared to outputs of the same age and source (98th percentile)

Mentioned by

news
9 news outlets
blogs
5 blogs
twitter
109 tweeters
facebook
10 Facebook pages
wikipedia
2 Wikipedia pages
googleplus
2 Google+ users
reddit
1 Redditor

Citations

dimensions_citation
85 Dimensions

Readers on

mendeley
353 Mendeley
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Title
Omega-3 fatty acids for depression in adults
Published in
Cochrane database of systematic reviews, November 2015
DOI 10.1002/14651858.cd004692.pub4
Pubmed ID
Authors

Katherine M Appleton, Hannah M Sallis, Rachel Perry, Andrew R Ness, Rachel Churchill

Abstract

Major depressive disorder (MDD) is highly debilitating, difficult to treat, has a high rate of recurrence, and negatively impacts the individual and society as a whole. One emerging potential treatment for MDD is n-3 polyunsaturated fatty acids (n-3PUFAs), also known as omega-3 oils, naturally found in fatty fish, some other seafood, and some nuts and seeds. Various lines of evidence suggest a role for n-3PUFAs in MDD, but the evidence is far from conclusive. Reviews and meta-analyses clearly demonstrate heterogeneity between studies. Investigations of heterogeneity suggest differential effects of n-3PUFAs, depending on severity of depressive symptoms, where no effects of n-3PUFAs are found in studies of individuals with mild depressive symptomology, but possible benefit may be suggested in studies of individuals with more severe depressive symptomology. To assess the effects of n-3 polyunsaturated fatty acids (also known as omega-3 fatty acids) versus a comparator (e.g. placebo, anti-depressant treatment, standard care, no treatment, wait-list control) for major depressive disorder (MDD) in adults.  SEARCH METHODS: We searched the Cochrane Depression, Anxiety and Neurosis Review Group's Specialised Registers (CCDANCTR) and International Trial Registries over all years to May 2015. We searched the database CINAHL over all years of records to September 2013. We included studies in the review if they: were a randomised controlled trial; provided n-3PUFAs as an intervention; used a comparator; measured depressive symptomology as an outcome; and were conducted in adults with MDD. Primary outcomes were depressive symptomology (continuous data collected using a validated rating scale) and adverse events. Secondary outcomes were depressive symptomology (dichotomous data on remission and response), quality of life, and failure to complete studies. We used standard methodological procedures as expected by Cochrane. We found 26 relevant studies: 25 studies involving a total of 1438 participants investigated the impact of n-3PUFA supplementation compared to placebo, and one study involving 40 participants investigated the impact of n-3PUFA supplementation compared to antidepressant treatment.For the placebo comparison, n-3PUFA supplementation results in a small to modest benefit for depressive symptomology, compared to placebo: standardised mean difference (SMD) -0.32 (95% confidence interval (CI) -0.12 to -0.52; 25 studies, 1373 participants, very low quality evidence), but this effect is unlikely to be clinically meaningful (an SMD of 0.32 represents a difference between groups in scores on the HDRS (17-item) of approximately 2.2 points (95% CI 0.8 to 3.6)). The confidence intervals include both a possible clinically important effect and a possible negligible effect, and there is considerable heterogeneity between the studies. Although the numbers of individuals experiencing adverse events were similar in intervention and placebo groups (odds ratio (OR) 1.24, 95% CI 0.95 to 1.62; 19 studies, 1207 participants; very low-quality evidence), the confidence intervals include a significant increase in adverse events with n-3PUFAs as well as a small possible decrease. Rates of remission and response, quality of life, and rates of failure to complete studies were also similar between groups, but confidence intervals are again wide.The evidence on which these results are based is very limited. All studies contributing to our analyses were of direct relevance to our research question, but we rated the quality of the evidence for all outcomes as low to very low. The number of studies and number of participants contributing to all analyses were low, and the majority of studies were small and judged to be at high risk of bias on several measures. Our analyses were also likely to be highly influenced by three large trials. Although we judge these trials to be at low risk of bias, they contribute 26.9% to 82% of data. Our effect size estimates are also imprecise. Funnel plot asymmetry and sensitivity analyses (using fixed-effect models, and only studies judged to be at low risk of selection bias, performance bias or attrition bias) also suggest a likely bias towards a positive finding for n-3PUFAs. There was substantial heterogeneity in analyses of our primary outcome of depressive symptomology. This heterogeneity was not explained by the presence or absence of comorbidities or by the presence or absence of adjunctive therapy.Only one study was available for the antidepressant comparison, involving 40 participants. This study found no differences between treatment with n-3PUFAs and treatment with antidepressants in depressive symptomology (mean difference (MD) -0.70 (95% CI -5.88 to 4.48)), rates of response to treatment or failure to complete. Adverse events were not reported in a manner suitable for analysis, and rates of depression remission and quality of life were not reported. At present, we do not have sufficient high quality evidence to determine the effects of n-3PUFAs as a treatment for MDD. Our primary analyses suggest a small-to-modest, non-clinically beneficial effect of n-3PUFAs on depressive symptomology compared to placebo; however the estimate is imprecise, and we judged the quality of the evidence on which this result is based to be low/very low. Sensitivity analyses, funnel plot inspection and comparison of our results with those of large well-conducted trials also suggest that this effect estimate is likely to be biased towards a positive finding for n-3PUFAs, and that the true effect is likely to be smaller. Our data, however, also suggest similar rates of adverse events and numbers failing to complete trials in n-3PUFA and placebo groups, but again our estimates are very imprecise. The one study that directly compares n-3PUFAs and antidepressants in our review finds comparable benefit. More evidence, and more complete evidence, are required, particularly regarding both the potential positive and negative effects of n-3PUFAs for MDD.

Twitter Demographics

The data shown below were collected from the profiles of 109 tweeters who shared this research output. Click here to find out more about how the information was compiled.

Mendeley readers

The data shown below were compiled from readership statistics for 353 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
United Kingdom 2 <1%
United States 2 <1%
South Africa 1 <1%
Australia 1 <1%
Unknown 347 98%

Demographic breakdown

Readers by professional status Count As %
Student > Bachelor 80 23%
Student > Master 74 21%
Researcher 50 14%
Student > Ph. D. Student 23 7%
Student > Postgraduate 17 5%
Other 56 16%
Unknown 53 15%
Readers by discipline Count As %
Medicine and Dentistry 114 32%
Nursing and Health Professions 56 16%
Psychology 23 7%
Agricultural and Biological Sciences 19 5%
Neuroscience 13 4%
Other 59 17%
Unknown 69 20%

Attention Score in Context

This research output has an Altmetric Attention Score of 174. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 14 September 2019.
All research outputs
#93,165
of 14,562,081 outputs
Outputs from Cochrane database of systematic reviews
#197
of 11,019 outputs
Outputs of similar age
#2,568
of 283,157 outputs
Outputs of similar age from Cochrane database of systematic reviews
#5
of 250 outputs
Altmetric has tracked 14,562,081 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 99th percentile: it's in the top 5% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 11,019 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 22.3. This one has done particularly well, scoring higher than 98% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 283,157 tracked outputs that were published within six weeks on either side of this one in any source. This one has done particularly well, scoring higher than 99% of its contemporaries.
We're also able to compare this research output to 250 others from the same source and published within six weeks on either side of this one. This one has done particularly well, scoring higher than 98% of its contemporaries.