Yeah the only ones I can think of that used to be used the current medical way are cannabis for appetite and analgesia and psychadelics for ptsd and addiction. Both of these examples are obvious to anyone who’s used such substances.

Cannabis just makes you hungry and hurt less. Traumatized people who do psychedelics tend to revisit their trauma in new lights and having a guide to help with it is something a lot of people figured out was a good idea.