Not understanding the mechanisms of psychiatric medications is the norm, from what I understand with my limited knowledge of psychiatry. The brain very poorly understood compared to the rest of the body. Not knowing how exactly something works doesn't make it any less effective anyways, it's a small miracle there are so many effective drugs for so many disorders with how little knowledge researchers have to work with.

We don’t really understand why anesthesia works, but I’m still going to opt for it if I have surgery.

https://en.m.wikipedia.org/wiki/Theories_of_general_anaesthe...