I can’t remember who sent this along, it was a while ago and I just got around to reading it. Interesting comment at the end:

It’s not clear to me why the cure of possession by the use of psychoactive drugs would seem unreasonable if, in fact, the vulnerability to this state had been induced by some ingested substance. I believe that practitioners of Voodoo, as well as shamans of numerous cultures, are reported to use ingested substances to facilitate their possession by discarnate entities. Many pharmaceuticals have an antidote which produces the opposite effect, and the anti-schizophrenia drug administered could well have brought about this effect, closing the open portal in the central nervous system of the patient.

Full Story: Mind Hacks: Classic case: Psychiatric treatment of ghost possession