The sample collection time was the source of high heterogeneity (the subgroup of sample collection time within 1 day: I<sup>2</sup> = 17%, p < 0.001).<h4>Conclusion</h4>Higher peripheral IL-6 concentrations in the acute stage of stroke are closely related to the risk of PSD; collecting samples within 1 day after stroke onset and evaluating depression post discharge are recommended. This evidence concerns the gene IL6 and major depressive disorder.