Dennis McKenna – The Screaming Abyss

Our guest this week on London Real is the psychedelic researcher Dennis McKenna.

Dennis is brother to the late Terence McKenna who pioneered the use of plants as away to positively alter human consciousness.

Dennis and Terence blazed the trail for modern psychedelic experimentation as part of a group known as the Brotherhood of the Screaming Abyss.

This was a group of Berkeley students who went down to Columbia in the early seventies in search of DMT.

Given the fact that you are a London Real fan I am going to assume that you already understand the importance of psychedelics in my own personal journey.

Terence McKenna is something of a patron saint for the show.

His visionary lectures on consciousness, culture, the arts and natural drugs are legendary and continue to be a resource for people like myself who use such substances to explore and expand their own minds.

Both Terence and Dennis come from a different age in many respects, an age when spirituality, music, literature and drugs all went hand in hand, and when being called a rebel was still a compliment.

Forming a formidable team, Terence was the learned preacher, and Dennis was the researcher.

The two would travel America and the world bringing the gospel of mind enhancement through natural plants.

Both of them committed their lives to the idea that the reality we see in the everyday is not even a dot on the the true reality beyond our senses.

If you have never tried psychedelics, then this kind of talk is going to seem downright weird.

But like his late brother, Dennis is a very articulate, humorous and kind soul, who will immediately win the trust of any of you sceptics out there.

This is no ageing hippy spouting claptrap! This is a scholar of natural psychedelics, a man learned in science and the humanities.

Dennis has a perspective on the mind and its relationship to culture which is informative and revelatory.

Something which will strike you right away about Dennis is his ability to get deeply vulnerable about his story, his relationship with his brother, and his own flaws.

Dennis pretty much bears all in regards to his relationship with Terence — the comradeship and the fallings out, and the traumatic experience of watching his brother succumb to brain cancer.

For anyone watching this who is already a fan of Terence McKenna’s work, this might be a little painful too, when you hear how much suffering there was in the great man’s last decade.

Dennis tells me about the self-doubt, conflicts and personal trials Terence went through in his final years leading up to his disease, and also speaks about their own disagreements as brothers.

As two Irish-American brothers from Colorado, their relationship was intensely close, and even difficult.

Dennis’s book The Brotherhood of the Screaming Abyss, was self-published in 2012.

He tells me the book was as much a way of healing the grief of losing Terence as it was a way of recounting the facts of his journey with his brother.

A point to look out for in this absorbing discussion with Dennis is what he thinks of the influence of his brother’s message, and the work he and Terence were doing in the eighties and nineties.

It’s so difficult for us to imagine now, but back in the day plant psychedelics were extremely taboo, and people who advocated their use were thought of as quacks and frauds.

Dennis himself is surprised by the transformation in the last twenty years, and he tells me it is still hard to believe that Ayahuasca that basically become a household name, and pretty much mainstream.

Dennis is convinced that a lot of this can be attributed to his brother’s visionary stubbornness, and his willingness to just keep talking when everyone else was too scared to speak out.

Still a believer in the power of plant medicines, Dennis regards these substances the same way indigenous peoples have done for centuries. Not as drugs but as teachers.

Man’s relationship to nature is something that needs to be revolutionised and Dennis believes that Ayahuasca is reaching out to humanity with a message of oneness with nature.

Dennis recalls that first journey he and Terence did to Columbia in search of DMT.

Frankly, it’s an outrageous, enlightening and at times unbelievable tale of insanity and spiritual awakening!

These guys were really pioneers in the early seventies, and they had very little to rely on but their own scientific discipline and a passionate belief that plant substances had something to teach human kind.

If you remotely curious about what Terence McKenna was like as a man, then you are going to love Dennis’s discussion about his brother’s ability to capture an audience.

Dennis is outspoken about his frustrations with Terence over the wild and bizarre things he could get away with saying.

But Dennis also speaks with with pride and affection about his brother’s poetic and shamanic gifts.

Terence McKenna was revered for his articulate power as much as anything else, and Dennis and I talk about this.

Dennis tells me his brother’s saving graces were his commitment to independent thinking, and his ‘Irish twinkle’ or sense of humour.

Though he was, and still is, a kind of counter-culture icon, Dennis insists that Terence never wanted to be a guru.

He simply wanted to kick-start
self-awareness and independent thinking
in his audiences.

It’s fascinating to hear an intimate brother’s take on why Terence was so good at doing that, and why he continues to have an impact even to this day.

As well as talking at length about his brother as a man and an icon, Dennis and I have some interesting discussions about his own views on plant medicines, dosages and his own take on the meaning of the psychedelic experience.

Dennis is a scientist and scholar in his own right, and has contributed to the present day open-mindedness about consciousness-expanding substances.

Whatever your take on psychedelics is, and whatever you feel about our beloved plant allies, you’ll find this episode one of those special London Real experiences.

Dennis is a warm-hearted, gracious man, and has that same intonation and lilt of his brother, and in many ways Terence was in the room with us during the filming of this episode.

So sit back, relax, and enjoy the rest of your Sunday and join us in the Screaming Abyss.

London Realer, I give you Dennis McKenna.

[0:08:20] Introduction, Going on an adventure with Terrence.

[0:10:40] Don’t let the facts stand in the way of a good story.

[0:12:50] Kickstarter campaign that raised more money than any other books – $90,000 raised.

[0:17:00] A personal story.

[0:18:00] When Terrance died.

[0:25:00] Alternative treatments on the brain tumour.

[0:27:00] Response from the community when Terrance died.

[0:29:00] Terrance has never really gone away. He’s a ghost on the internet.

[0:32:00] Are you surprised how quickly plant medicine became so popular.

[0:35:00] MDMA and prescription drugs. Psilocybin.

[0:37:00] Talking about these stuff in the 1980’s.

[0:39:00] Social transformation in the view of Ayahuasca.

[0:40:00] Ayahuasca our screwed up relationship with nature.

[0:45:00] La Chorrera in Columbia. Discovery of DMT. LSD was a drug. DMT was a message from the future.

[0:47:15] Verola.

[0:48:50] Screaming Abyss

[0:53:00] Akuhai

[0:56:00] Mushroom. Downloading funny ideas.

[1:00:00] Experiments at the La Chorrera.

[1:02:40] Becoming psychotic for 2 weeks.

[1:07:30] The experiment was unfolding. Writing.

[1:10:00] Working out the cycles when it will come back.

[1:11:50] The Time Wave Theory.

[1:13:10] I was always sceptical of the Iching.

[1:15:20] the mistake in the Time Wave.

[1:16:50] Really wanted to believe in the idea.

[1:18:00] Conceptually challenged. He was a poet. It was his voice. He was a shaman.

[1:20:00] Glossolalia. Imitate this glossolalia and speak this gibberish.

[1:21:35] Did he train to speak that way?

[1:22:00] Living in this hippy house.

[1:22:48] I love listening to him. Say to craziest thing that seem to sound rational.

[1:23:40] Who’s a modern day Terrance?

[1:24:30] Here’s a bunch of interesting idea. Think for yourself. Never selling anything.

[1:26:00] Invested in the idea that people has a their own mind. There’s always room for humour.

[1:28:40] There’s lots of stuff going on and there’s  a lot to learn. The world is querer that you can possibly imagine.

[1:30:00] Ayahuasca is a good teacher. We are curious monkeys.

[1:34:00] Psilocybin: Magic Mushroom Grower’s Guide.

[1:39:00] Visionary paintings. Luis Eduardo Luna – Ayahuasca Visions: The Religious Iconography of Peruvian Shaman.

[1:41:00] I just work for the plants.

[1:42:00] Symbiosis is what the plants want. Michael Pollan – did we domesticated corn or has corn domesticated us?

[1:43:00] The biosphere or Gaia has put all the eggs in one basket in us.

[1:44:50] We don’t need to grow the mushrooms to earn the right to try them.

[1:46:00] The heroic dosage.

[1:48:20] Abyss will open up. Mushrooms vs ayahuasca. Mushrooms are just as profound.

[1:50:30] The importance of setting. Safety. Intention. The set. Who you are. The mind set.

[1:54:35] Mushrooms is more like downloading a map.

[1:56:00] Mushrooms, ayahuasca and DMT are all tryptamine

[1:57:00] Did Terrance stop taking psychedelic?

[2:00:00] Excuse for not taking psychedelic. On going conversation.

[2:03:40] Graham Hancock.

[2:07:40] Myths of the big flood, volcanoes, and earthquake. Archeology.

[2:09:25] Graham and his psychedelic experiences.

[2:11:00] Success secrets.

[2:12:10] Plants are intelligent. The Intelligent Plant – Michael Pollan.

[2:15:20] Advice to the 20 year old Dennis McKenna.

[2:16:00] Best advice ever received.

[2:22:00] What would you tell Terrance.

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Much appreciateed ! Cheers 😊


Was such a joy to listen to this interview! Thank you.


Very nice intro. Perfect. This was a true gift. Thank you.


Very nice intro. Perfect.


Thank you very much for this interview 🙂

Paolo Papoose Pesce

… great thinkers, the both of the McKenna brothers; i’ve named my design company Divergent Consciousness after reading Terence books and listen to Dennis speeches.


That explains whey Dr Guzman did not allow a mushroom to be named after Terrence & Dennis McKenna.


[…] In this episode of London Real, host Brian Rose sits down with author and ethnopharmacologist Dennis McKenna to talk about his book, The Brotherhood Of The Screaming Abyss, which chronicles his time spent with his brother, Terence. In their discussion, Dennis speaks about the “Heroic Dose,” his time spent with Terence at La Chorrera, Panama, the misconceptions that people have about psilocybin, plunging into the abyss, the importance of set/setting/intention, C.G. Jung’s Psychology and Alchemy, and more. Check out a small segment from their talk in the video below and hear the full discussion by visiting […]


I’d like to point out that it was Curandera María Sabina through R. Gordon Wasson’s article in Life Magazine that made the mushrooms known to the western world. Not to discredit Terence nor Dennis, and I’m sure they agree.


Excellent interview, though I’m saddened by how often Dennis uses the word “crazy”.

CA Howard

Excellent interview..thank you! <3

Tara Haghighi Yacalis

great interview! very intense, emotional, honest and informative … you are a good interviewer!

Timothy Solomon

“Terence never had anything to sell…and would have been a ‘false prophet’ had he been in it for the money…”
shortly after this is stated…
scumbag brian withholds one of Dennis’ answers as bait for paid membership to his site…

If you wanted to teach someone what hypocrisy was, this would be a textbook example.

The psychedelic experience is an intellectual endeavor, not a financial one.

Julius Vladimir Francisco

True that.


I was going to say something similar. The move seems sly unless Dennis got $$$, whether or not he endorsed it.




Out of all 150+ minutes of intellectual talk and exchange you find only this to point out! I agree it would be nice to have the content completely free, but how do you think the show pays for production and some guest? Unfortunately we live in a world that is regulated via financial and administrative systems, for one to be able to reach such a large audience with such an eclectic variety of ppl would exhaust substantial resource of both. I mean you called Brian a scumbag… based on what? Can give intelligent and articulated proof of this? You also… Read more »


Hi. I understand what you’re saying but the sad fact is that we don’t currently live in a free world. We all have bills to pay and not only that but production costs too. It would be impossible for us to do London Real without monetising it somehow so we do what we have to. You say that Brian withheld one of Dennis’s answers to bait people into joining the site and you’re right, but what you forget is that this is one out of maybe 40 questions that were asked during the interview. There is over an hour and… Read more »

John Yin
John Yin

Thanks for the interview – love Dennis…

Andrew Cooper

Mind = Blown

Eduardo Rivera

People react like molecules..Twinge them about and they react similarly..

Eduardo Rivera

Too many variables for one.

Eduardo Rivera

Nature is the better chemist.

Can San

Great interview, thank you !

Maria Alcazar

Great interview!!!! Brilliant

Fredric Sandsrtröm

Great interview of a brilliant mind and person, really enjoyed it.

Cat Cat

Looooooooved it!! Thank you!

Rhys Hutchinson

Awesome interview mate , you do a really good job .

Rek Init

The host asks, “What would be the equivalency of Terence McKenna?” I would’ve answered Alan Watts, but I suppose he’s interested in someone that’s alive. If that’s the case, then Kilindi Iyi is your man, Brian.

Rhys Hutchinson

Kilindi hasn’t done ayahuasca and a bunch of other stuff but when it comes to balls in doing. 30 plus grams he’s the man .

Benja Min

WOW. Thank you Brian for that interview. I, like many people, have spent hours upon hours enjoying old Terrence Mckenna talks. Dennis really nailed it in the interview where he said that Terrence was a poet and had a way of almost hypnotizing people with his voice, tone, vocabulary and the way that he wove incredibly novels ideas together with knowledge from so many other interests of study. He is one of, if not my most favourite person to listen to online, he’s so entertaining and never gets old to me. I wish so much that he would have stuck… Read more »

Christopher Wallace

it would be lovely if we had Alexandro jodorowsky on London real..

Jeff Stasi

just found this so cool smiling all the way is right I met Terrence a few times in Occidental.
best conversationalist and fun conversations …thankyou !!!!!

Mark Anthony Kushington

Terrence Changed my Life.. He Made Me realize we are not aliens for these substances and to experience your own damn reality.. thankyou Brian For the Share.. Really Enjoyed Listening to this.. i Spent the whole summer tripping and listening to terence Dennis Alan Watts Jung.. learning a Lot from mushrooms LSD and MDMA.. DONT THANK ME THANK THE PLANTS.. DENNIS HAS IT RIGHT,, TREES GIVE OXYGEN plants shamanism its all symbiosis

andreas strömberg

Thanks for an amazing interview. You should check out Mycologist Paul Stammets a realy interesting person.

Jimmi A. Mortensen

such a nice episode.. thx brian , i learned alot . he is very much a clever man, that dennis mckanna, and as a danish listener i understand more compared to when i listen to the brother terrence mckanna.. the other side of the coin.

Roger Anthony Essig

Great discussion, great questions

Brian Gard


Drumstick Cph

Interesting and enlightening to finally meet Dennis McKenna. As a student of psychedelics and Terence McKenna for almost 20 years, I first encountered Dennis in the audio book version of “True Hallucinations” (a recommendable 9 hr version is available on YouTube), in which Terence, Dennis and a few other pioneers travel to South America in 1970 to experience different alternative realities through marijuana, psylocybin and ayahuasca. Around 40 minutes in, Dennis says that it’s a positive sign for the Earth that influential people like CEOs are taking the ayahuasca trips and return home with sustainable ideas for the environment. I… Read more »

Brian Rose

cheers to you sir, I truly enjoyed my time with Dennis. As a long-time listener of Terence I felt a very special connection (hope it showed!)

Arwa Stone
Arwa Stone

What an awesome guest!!! Leant so much about psychedelics and plant intelligence.

Alexandrina Stubbs

I met and experienced plants intelligence and to me they have better instruments of perceptions and communication than us. We have rudimentary instruments of receiving their messages. Their contribution to our life and to the planetary life is extraordinary and we refuse to open our hearts and minds to understand it. just think how many life beings we eat in a hand full of seeds. I am grateful to McKenna brothers for their work.

Simon Vigneault
Simon Vigneault

Thanks very much for this. I’ve always been curious about Dennis McKenna, his role in Terrence’s work and life, and his own work. It was wonderful to hear him speak in such an intimate and open conversation. Great stuff.

Espen H Rathe

Thank you for this interview. Gracias

Al Hall

Thanks Brian

Good to see this one. I discovered Terrance’s stuff there year after he died. He was a huge influence on me too.



@39:00 – My guess about whats going on is…9/11 happened followed by 2 pointless wars that has plunged most of Europe and America into disparity and never ending strife (war on terror), people don’t trust the authorities to know what their actually talking about nor believe they have the best interest of the people, confidence in politics and the legal system has been irreparably damaged. Heavy dissolution seeped in and so the realization that people with overinflated egos who crave power over others to dictate the way they live their lives in contrast to how they live own has serious… Read more »

Stevie JT

Fantastic episode! What an absolute pleasure! Definitely one of your best episodes, Brian. I found London Real when reading up on Ayerhuasca. I had already done a ceremony a few years back and discovered the joys of listening to Terence. Then one day I was surfing some You Tube/Terence/Ayerhuasca and I came across London Real – so yes, the plants, they are bringing us all together! Keep up the great work Brian.

Alexa and Ruthless

Great conversation! I Love anything the McKenna brothers are, and have been, involved with. I also like the bit at the end where Brian admits that Terrence had a huge impact on his life after discovering him through the Joe Rogan Experience. This is the way it went down with me, too.

Tonia Briones

Kat Harrison, Terence’s ex wife, is perhaps one of the most knowledgeable people on all plant medicines. She has a deep and subtle perspective that I haven’t come across in the male-dominated narrative on entheogens . She teaches a bit , and there is some fantastic video with her , but very little for someone of her incredible experience and wisdom and of course it would be amazing to have her on London Real. I have learned so much from all the people out there, men or women, but the dialogue is still not balanced and it seems most people… Read more »

Paulo Sigerson

Great episode, thanks guys!

And as a suggestion on this subject it’d be really nice to have Jim Fadiman on the show.

Edward Bowyer

Second that, Jim would be a great guest

Cliff Moen

amazing talk, I love Dennis.
Very excited for the future of earth and these plant teachers!

Gal Ganor

I stumbled upod jung’s work and ideas a year and a half ago , and then stanislav grofs and his treatment with lsd and the holotropic breathwork . that brought me to Londonreals ayahuaska episode , and then MAPs work with mdma , i found myself constantly reading about psychedelics, researching about them . I found them facinating without ever having them . I wanted to try when I found out they’re much more than recreational drugs , but never felt prepared enough to face them. so i started meditating daily , and confronted my own beleifs and relations with… Read more »

Pato Vica

muy bueno !!!


Very nice.

Josh La Forte

Thank you so much. This was a real treat. I’d just like to say, it wasn’t ‘just’ the way Terence spoke, there was much substance to what he had to say about ~90% of the time. Dennis has continuously played this down. Where science fell short, Terence had some fun. Again, great interview and I’m really enjoying Brotherhood of the Screaming Abyss. Thank you, Dennis.

Josh La Forte

And thank you Brian 🙂

david alejandro

great talk, I’ve read the brotherhood of the screaming abyss and its an awsome book, it gets deep in the story behind Terence’s rap about life.

Liisi Olen

Thank you both so much for this!! I loved every second of it!

Vladan Bajic

great vid, should talk to daniel siebert and his journey with salvia divinorum……
best, v

Eftychia Panagiotou

Brian and his team work very hard to put everything together for us to enjoy effortlessly. I’m not really sure what your problem is.

Thiago Jota

This is awesome. And, as Dennis suggested, how about Graham Hancock back anytime soon?

Brian Rose

Please leave me your comments about my episode with Dennis!!! Namaste.

Eftychia Panagiotou

That was a great episode. One of my top favourites by LR! I love how grounded Dennis is. Yes, Terence’s voice is hypnotizing and his message is delivered by the energy of his voice more so than the words themselves. I am looking forward to exploring the world of psychedelics. I am familiar with other dimensions and beings, in fact the elves have made themselves known to me recently and although they felt mischievous at first, they are fun guides to have. As Dennis mentioned, it’s difficult to explain these things to people who aren’t open to experiencing them. It’s… Read more »


Brian, do you ever get the feeling that Terrance McKenna’s death was not just bad luck? possibly poisoned slowly over time? and according to wikipedia, “On February 7, 2007, McKenna’s library of rare books and personal notes was destroyed in a fire that burned offices belonging to Big Sur’s Esalen Institute, which was storing the collection. An index maintained by his brother Dennis survives, though little else.” I don’t believe he was very well received by certain people, it’s all a little too convenient to me that much of his written work has been destroyed… I personally don’t believe in… Read more »

Grant Headley

2 years ago I would have never imagined being interested in this man, now I can appreciate how this is one piece of the puzzle of the whole human experience.

Swithun Gibbs-kennet

What time are u releasing this one ?

Gal Ganor

Cant wait for this one

Timothy Cannata

Awesome! I’m a big Terence McKenna fan, I’ve listened to almost everything he recorded. His brother is awesome too, he’s got plenty of interesting things to say.