To the Editor: Mega-analysis is a powerful tool in solving difficult questions not answered by smaller studies or meta-analyses. However, we are concerned about limitations to the study by Mr Fournier and colleagues.1 First, mild MDD (HDRS 8-13) was evaluated in only 1 of the 6 studies.2 Furthermore, in that study the mean HDRS score was approximately 14, equivalent to moderate MDD. The number of patients with mild MDD was not included. Because sample sizes were 39 and 38 in the 2 groups, mild MDD was likely present in approximately 40 patients total. Drawing conclusions from such a small data set is problematic. Therefore, no conclusions should be made about mild MDD.
Hicks P, Hicks XP. Depression Severity and Effect of Antidepressant Medications. JAMA. 2010;303(16):1596-1599. doi:10.1001/jama.2010.508