Questions were received about the numbers on this article and we want to clarify this point for the readers:

“The text of the article emphasizes that approximately 17.5 million people are diagnosed with depression, based on your secondary database analysis. However, it is not clear from the text whether your analysis was based on data from 17.5 million people, or whether the analysis was based on a smaller subset of representative data.”

We believe the actual issue in the question is not about the numbers in the study here, it is about the full understanding of the MEPS database. Here we will try to simplify the concept for the readers.

The MEPS database is a very unique, it includes people in a very unique way (learn more about the MEPS database through their website) to represent the whole US population by including different people every year and follow them for two years to capture changes in the whole US population over the two years follow-up. Thus, when we say that “Over the duration of the study (2005–2016), on average there were 17.47 million adult patients diagnosed with depression disorder every year with two-year follow up.” that means from our sample of all people in the database between 2005 and 2016 (each year the database included about 13,000 people through a complex stratified sampling and assign weight on each participant in the sample to represent the US population for that year) we had a subset of patients that represented patients who were diagnosed with depression and had at least two-years follow-up (this is from the weighted sample not actual population, and we didn’t say that it is the actual sample in the paper, but there is a consensus that research that analyze this database is actually representative of the whole US population which is the main purpose of this database).

With that being said, this estimate is not actually purposed to represent all patients diagnosed with depression in the US every year (as we described in the study), as only patients with two-year follow-ups in the database with documented values for the HRQoL measures are included in this subset from the overall sample of all patients with depression in the database. This subset of the whole sample was selected to enable us to make the comparison in the change in HRQoL measures between the two groups in the study.
Therefore, this number will not be found on the MEPS database and it is reached by the described methodology in the study Figure 1 was designed to allow the understanding of this point in the paper.