Earlier quoted context omitted.
I might remove MDMA from that list -- the head researcher at Johns Hopkins for this study was interviewed about a similar 2006 study he did; it mentions that studies at John Hopkins have shown the potential for brain damage from MDMA ("certain nerve cells", anyway). http://www.hopkinsmedicine.org/Press_releases/2006/Griffiths...
It should be noted that there was a scandal involving MDMA research at Johns Hopkins. A study claimed to prove that MDMA caused brain damage, but in fact Methamphetamine had accidentally been administered instead of MDMA. http://www.wired.com/techbiz/media/news/2003/09/60328 Of course, this doesn't disprove other legitimate studies. The interview you link took place well after that scandal.
That said, for those who are interested, here is the paper that the article is referring to:
Griffiths, R.R., Johnson, M.W., Richards, W.A., Richards, B.D., McCann, U., & Jesse, R. (in press). Psilocybin occasioned mystical-type experiences: Immediate and persisting dose-related effects. Psychopharmacology.
... and here is the previous study he did:
Griffiths, R.R., Richards, W.A., McCann, U., & Jesse, R. (2006). Psilocybin can occasion mystical experiences having substantial and sustained personal meaning and spiritual significance. Psychopharmacology, 187, 268-283.
...which was the study related to the aforementioned interview: http://www.hopkinsmedicine.org/Press_releases/2006/Griffiths...