What Dennis McKenna Believes

“Dennis McKenna became one of the most rigorous neuropharmacologists working on tryptamines. His assessment of what happened at La Chorrera, calibrated, affectionate, skeptical, is the other side of True Hallucinations.”

Dennis McKenna's memoir, The Brotherhood of the Screaming Abyss (2012), provides the other account of La Chorrera, written by the person who, by all evidence, went furthest into the altered state and came back most intact.

Dennis recalls the episode with clarity that his brother's True Hallucinations does not always provide. His assessment is careful: something happened at La Chorrera that was extraordinary. The nature of what happened, whether it was a genuine encounter with plant intelligence, a pharmacologically induced psychosis, or something between, he does not definitively resolve. What he has said in interviews is that he does not believe the specific claims Terence made (the Timewave, the alien mushroom intelligence) but that he cannot fully dismiss the experiential reality of what they both went through.

Dennis completed a doctorate in neuropharmacology at the University of British Columbia and spent decades doing rigorous scientific research on tryptamines, ayahuasca pharmacology, and the interaction between psychedelic compounds and human neurobiology. His scientific work is careful and precise. It coexists with his account of La Chorrera in ways he navigates openly: he doesn't let the experience override his scientific judgment, and he doesn't let his scientific training negate the experience.

He has spoken about Terence's brain tumor, the glioblastoma that killed Terence in 2000, with a speculation that he acknowledges is unverifiable: that the decades of high-dose psychedelic use may have had a relationship to the tumor. He does not state this as fact. He states it as something he wonders about, as a neuropharmacologist who loves his brother.

The relationship between the two brothers is the human center of True Hallucinations, more interesting, finally, than the theories. Dennis's ongoing presence as a scientist, commentator, and advocate for rigorous psychedelic research is the most concrete evidence that La Chorrera produced something real, whatever that something was.

Sources

• D. McKenna, The Brotherhood of the Screaming Abyss (2012)
• D. McKenna, various interviews 2010-2025 [Source not found; under review]
• Wikipedia, Dennis McKenna