Induction, not intoxication
Drumming, song, dance, fasting, cold, heat, isolation, sleep restriction, breath, pain and — in some traditions — plants are all used. Most traditions worldwide use no psychoactive substance at all.
Journey versus possession
A common analytic distinction: in journey models the specialist's soul travels; in possession models a spirit arrives and speaks. Many traditions do both, or describe something the distinction does not capture.
Cultural scripting
What is experienced, how it is narrated, and whether it counts as successful are all shaped by tradition. The same physiological state produces very different reports in different communities.