[eurasiantiger]

Different cultures generally get exposed to foreign substances due to imperialism and capitalism, see the opium wars.

It’s obvious that original cultures have their own traditional substances, from fly agaric to psilocybe shrooms to cava to ayahuasca. They would be taken as a part of a prosocial setting, an initiation or a healing ceremony, and the inebriation would be seen as a transformative process: something that enables living fully. Alcohol, on the other hand, tends to only disable and provide a means to escape stress.

What happens to the aforementioned shaman culture once western values and substances are introduced?

I would assume the increase in ego-centric stress drives the population into escape mode, and the imperialist offers alcohol.