Wake Up Call for Insomnia GWAS

Here is another GWAS, this time for insomnia, that I think buries the lead:

Genome-wide meta-analysis of insomnia in over 2.3 million individuals implicates involvement of specific biological pathways through gene-prioritization

Here's an alternate title:

Based on 1.3 million GWAS, the maximum variance explained was 2.6% and based on 2.3 million individuals the maximum variance explained seems to be only 2% !

- (Hat tip to Veera M. Rajagopal, twitter handle: @doctorveera, who might not really appreciate the hat tip)

Obviously, there is a problem here, when, even when finding novel loci by expanding your dataset, you are getting getting worse "variance explained" from your PRS. I think this suggests that they have already reached their peak, which seems to run in the 2 to 3% range for most behavioral traits. I will once again point out that even this number is suspect, since it is not compared to any null trait. They try to rationalize it by suggesting that that the added data (from 23andMe) was less stringently phenotyped, but you can't have it both ways. Expanding datasets does not appear to give us any more real insight. It just bumps up the number of loci meeting significance, which arguably just a collection of false positives.

As the datasets expands beyond just white Europeans, I suspect this will onlly further water down the success of these studies, since they will not be able to rely as much on pop strat to get correlations.