A paper by Griffiths and colleagues has just appeared in the OnlineFirst archive of the Journal of Psychopharmacology. It describes a 14 month followup to their original paper on the spiritual and other effects of psilocybin consumption in humans.
The summary is short and sweet.
The current cite for the in-press article is:
Mystical-type experiences occasioned by psilocybin mediate the attribution of personal meaning and spiritual significance 14 months later R R Griffiths*, W A Richards, M W Johnson, U D McCann, and R Jesse, Journal of Psychopharmacology 2008, doi:10.1177/0269881108094300
For background, I detailed the first paper here in a prior post entitled Finding God in the Brain: That Psilocybin Study, after reading this post on several God-in-the-brain topics over at Terra Sigillata. I summarized the findings of the original Hopkins study:
It all boils down, however, to people having experiences quite consistent with other classical hallucinogens, that were rated as being "personally meaningful" two months later and that caused positive attitude, social and/or mood effects (by self report and with external verification).
and then mused:
Does this get us closer to a science of religion? Of understanding individual differences in religiosity? Perhaps. I certainly find it fascinating. It might give us a toehold on individual differences in, say 5-HT2A/C receptor expression or function, that pre-dispose one to religion. To plasticity in such systems that might result from religious experience. To understanding the mechanism that are involved in the more flamboyant behavioral expressions of religious ferver.
The conclusions of the most recent paper are simple- the effects on positive attitude, mood and social behavior are still there 14 months later and a majority of the people still consider this one of their top 5 personal and spiritual experiences.
A more extensive summary is up at the Psychedelic Research blog.