I wonder how much of the "crazy dreams" comes down to people usually taking such a drug when travelling and having new experiences/seeing new places/expanding their mental schemas (which is known to increase BDNF / promote neuronal plasticity, and therefore likely to cause intense dreaming under the "memory reconsolidation" hypothesis of dreaming.)

It'd be interesting to compare to the dreams of people who take the drug without travelling, e.g. medical staff native to malarial regions, who take it as a prophylactic when interacting with malaria-infected patients.