I've read of psychedelic research done in Mexico, Portugal, Switzerland, and the Netherlands. MAPS has information on some international studies being carried out on psychedelics.[1] Erowid probably has some too.[2]

(Curious how MAPS is HTTP and Erowid is HTTPS.)

[1] - http://www.maps.org/research

[2] - https://www.erowid.org/psychoactives/research/