DRD2 and major depressive disorder: Given that elevated blood levels of PRL were found in more than one third of PCOS women [16], and due to our previous findings of PRL contributing to T2D and depression [31], both phenotypes associated with PCOS [6, 32], it is also possible that some DRD2 variants might impair PRL secretion regulation and indirectly impair gonadotropin secretion and reproductive cycles.