Within seconds of inhaling 5-MeO-DMT, the most powerful psychedelic in the world, the familiar structure of reality dissolves entirely. 

Unlike other psychedelics drugs, such as LSD or psilocybin (magic mushrooms), which appear to ‘construct’ worlds of experience, for example by inducing visually intricate geometric hallucinations, 5-MeO-DMT is unique for its ability to strip away all sensory and mental content. 

5-MeO-DMT often plunges the individual into a state described as a ‘void,’ ‘non-duality,’ or ‘pure awareness,’ where the sense of self, time, and space completely vanish while consciousness remains paradoxically awake. However, whilst other psychedelics have been widely studied, the effects of 5-MeO-DMT on the human brain have been largely unexplored in human neuroscience. This is despite its current involvement in clinical trials for the treatment of depression, bipolar and alcohol use disorders.

The current study, published in Cell Reports measured the brain’s electrical activity in 29 participants who inhaled a high dose of vaporized synthetic 5-MeO-DMT using electroencephalography (EEG).

Following inhalation of the psychedelic, the researchers observed that slow brain waves surged dramatically. Normally, these waves travel forward and backward across the cortex, helping different regions communicate. However, under 5-MeO-DMT they fragmented into chaotic, short-lived waves that travelled across the brain in unusual directions. 

Figure showing that 5-MeO-DMT induces diffuse high-amplitude slow oscillations
5-MeO-DMT induces diffuse high-amplitude slow oscillations. From Blackburne et al, Cell Reports.

Slow brain waves play a crucial role in regulating states of consciousness. They are associated with reduced perception, e.g. deep sleep, aesthesia or coma, however participants were awake and aware of having a profound experience.

The researchers also found that these peculiar slow-wave effects pushed the brain as a whole towards an unusually simple and stable state. Instead of constantly shifting between states, the researchers observed that the brain settled into a low-dimensional pattern, making big changes harder to achieve. 

This unusual stability may explain why some people describe the experience of everything familiar ‘falling away’, because its simplicity could prevent the brain from being able to represent the complex categories that normally make up our world.

Talking about the findings, first author George Blackburne (Division of Psychology and Language Sciences), said: “These findings challenge long-held assumptions that slow brain rhythms always signal unconsciousness, instead it may be more to do with how these phenomena unfold in space and time together across the brain.

“5-MeO-DMT radically reorganises the human brain to create this unique state of ‘deconstructed consciousness’. The brain appears unable to formulate the distinctions that usually structure our lived experience, yet it continues to produce the fundamental sensation that we are indeed experiencing something, and that something is quite extraordinary. We believe this is a significant step in investigating how to subtract extraneous elements of subjective experience, and get at the core neurobiology of consciousness.”

Commenting on the significance of these findings and potential avenues for research, computational neuroscientist Professor Christof Koch, Meritorious Investigator at the Allen Institute said: “The findings reported in the study by Blackburne et al. advance our understanding of the physiological effects of 5-MeO-DMT on the human brain and open future avenues of research. The accumulated EEG data, once openly available, could be mined to identify potential biomarkers for “mystical” or “peak” experiences that drive therapeutic efficiency, or for loss of consciousness using perturbational complexity.”

 

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