On 2015 May 21, ALEXANDER TSAI commented:

The measures of n-3 and n-6 PUFA intake used in this study have well documented construct validity, as supported by moderate-to-strong correlations with fatty acids measured in plasma and erythrocytes and adipose tissue, and by their ability to predict the incidence of relevant conditions such as coronary heart disease, type 2 diabetes, and macular degeneration. The experimental evidence for the use of n-3 in the treatment of depression is not conclusive. In the meta-analysis by Bloch & Hannestad (Mol Psych 2012;17:1272–1282), the estimated treatment effect was small in magnitude and not statistically significant. Even if one accepts the criticisms that were published in response to that study, the reanalyses (Mol Psych 2012;17:1163–1167) did not change the fundamental conclusion that any possible measurable effect of n-3 on depression is small and likely explained by publication bias.

On 2015 Mar 12, Dennis Embry commented:

One should consider this finding in the context of self-report on diet versus the studies using biological markers such the study by Lewis et al. http://www.ncbi.nlm.nih.gov/pubmed/21903029.

The correct conclusion ought not to imply that there is no "…evidence that intake of n-3 PUFAs or fish lowered the risk of completed suicide." One of the reasons that the questionnaire presents a grave difficulty is the ubiquity of n6 in American foods that people have no idea about—even nurses. Few people realize for example that virtually all packaged baked goods in grocery stores contain significant n6. And snacks like a 1oz bag of any chip-type product are about about 3/4's by weight n6.

The issue here is that present food questionnaires may be too course and insensitive to n3 and n6 ratios in any, which is the issue. Yes, the study has large numbers but larger numbers with insensitive instrumentation may be just large numbers. This null finding is not dispositive, given other data such as the military studies that have much finer analyses, plus the experimental studies that show considerable impact on the layers of impulsive, depressive and aggressive behaviors associated with n3 deficit and n6 surplus.

On 2015 Mar 12, Dennis Embry commented:

One should consider this finding in the context of self-report on diet versus the studies using biological markers such the study by Lewis et al. http://www.ncbi.nlm.nih.gov/pubmed/21903029.

The correct conclusion ought not to imply that there is no "…evidence that intake of n-3 PUFAs or fish lowered the risk of completed suicide." One of the reasons that the questionnaire presents a grave difficulty is the ubiquity of n6 in American foods that people have no idea about—even nurses. Few people realize for example that virtually all packaged baked goods in grocery stores contain significant n6. And snacks like a 1oz bag of any chip-type product are about about 3/4's by weight n6.

The issue here is that present food questionnaires may be too course and insensitive to n3 and n6 ratios in any, which is the issue. Yes, the study has large numbers but larger numbers with insensitive instrumentation may be just large numbers. This null finding is not dispositive, given other data such as the military studies that have much finer analyses, plus the experimental studies that show considerable impact on the layers of impulsive, depressive and aggressive behaviors associated with n3 deficit and n6 surplus.