An intriguing new study, led by scientists from Imperial College London’s recently launched Centre for Psychedelic Research, is shedding light on how one of the world’s most powerful psychedelic substances alters brain activity, rapidly shifting a person’s brainwaves into a state that resembles dreaming.
Dimethyltryptamine, or DMT, is a profoundly potent yet very short-acting psychedelic. When smoked or injected DMT’s overwhelming effects can take hold of a person in seconds. However, the drug is rapidly metabolized by the body, returning a person to normality in around half an hour.
DMT is the primary psychoactive component in ayahuasca, a traditional Amazonian psychedelic medicine. However, to make DMT orally active, and last a number of hours, it must be combined with compounds known as monoamine oxidase inhibitors. In simplistic terms, an ayahuasca experience is a little like a 15-minute DMT journey but slowed down to last anywhere from six to 10 hours.
The new research from Imperial College London capitalized on the short-acting nature of DMT to conduct a temporal investigation into how the drug alters a person’s brain activity across a 20-minute experience. Electroencephalography (EEG) was selected as the best imaging modality for the study as it was the most detailed way to capture the temporal effects of DMT on brain activity over a very short period of time.
Thirteen volunteers were administered DMT infusions while wearing EEG caps to capture brainwave activity. Lead author on the study, Christopher Timmermann, says the brain activity seen in his team’s study was quite unlike what has been identified with other more commonly known psychedelics.
“The changes in brain activity that accompany DMT are slightly different from what we see with other psychedelics, such as psilocybin or LSD, where we see mainly only reductions in brainwaves,” Timmermann says. “From the altered brainwaves and participants’ reports, it’s clear these people are completely immersed in their experience – it’s like daydreaming only far more vivid and immersive, it’s like dreaming but with your eyes open.”
The general pattern observed in the study was a collapse of alpha and beta wave brain activity in the first minutes of the drug experience. These brainwaves usually correlate with waking states, however, their drop did not result in a shift to a reduced state of consciousness similar to that seen in general anaesthesia. Instead, the researchers saw a rapid increase in delta and theta brainwave activity. These delta/theta oscillations have often been linked with transitions through different sleep phases, including REM dreaming, but the rhythmicity of these oscillations in the DMT experience are certainly unique.