Why does MDMA seem to reduce stuttering so much?

Why does MDMA seem to reduce stuttering so much? So lately I have been experimenting with this substance after reading people’s experiences with it, and I surely say that it eliminates my stuttering completely or at least almost completely, and I feel blocks a lot easier to overcome. Is it because it changes your mood and outlook of life in general, or maybe it temporarily fixes the mechanisms related to stuttering by chemical reactions, etc? What I find interesting is that it is the only substance that seems to help, for example, alcohol makes it much worse, and Xanax doesn’t seem to help at all.