In response to "Adherence to the Mediterranean diet and risk of depression a systematic review and updated meta-analysis of observational studies"

The growing interest in the association between dietary patterns and depression risk is reflected by an increasing number of meta-analyses conducted recently on this topic. One of these meta-analyses found no evidence of a significant association between adherence to a Mediterranean diet and depression, when using prospective studies. This is an interesting finding, yet it is largely inconsistent with other meta-analyses published within the same time frame. The aim of this letter is to identify key analytic decisions made in that meta-analysis that may help explain the findings, specifically those regarding study inclusion criteria, outcome selection, and coding that may have affected the results of the analysis. After conducting the subsequent re-analysis addressing these revised methodological decisions, these decisions were found to largely explain the reported null result. These new findings not only provide greater context for the results of the meta-analysis but also explain why the findings were inconsistent with the relevant literature in this field.