While this might be due to the small sample sizes and lack of tight control on covariates in the studies included in the meta-analysis, it is also possible that the antidepressant effect is only observed in those with established depression (with no effect on incident depression), or that it only applies to other GLP1-RAs (since semaglutide was not included in the meta-analysis). This evidence concerns the gene GLP1R and depressive disorder.