QEEG Studies of the Acute Effects of the Visionary Tryptamine DMT

Abstract

Recent brain imaging studies in Psychedelic Brain Science are breaking new ground in our understanding of neurological substrate of biological consciousness in humans. The emerging field of inner experience and neuroscience is particularly well suited to the reexamination of the actions of psychedelics on subjective conscious experience. This approach is best understood as neurophenomenology. My work over the last few years has focused on the EEG correlates of the visionary tryptamine DMT action.  I believe the researcher must also have the drug experience as part of the experimental protocol, in order to fully understand the richness of the phenomenon. The objective of this exploratory research was to examine the QEEG correlates of the psychoactive smoked inhalation of exogenous DMT action.  Known as a potent visionary tryptamine, DMT  is ubiquitous in nature and has also been localized in the brain and peripheral tissues of mammals, including humans. The exact function of this endogenous DMT is the subject of ongoing neuropharmacological  research.

Three sources of DMT were tested: high purity synthetic 5-MeO- DMT, Bufo 5-MeO-DMT (an extract from the Sonoran desert toad venom, Bufo alvarius), and N,N- DMT from a natural extract of the Acacia tree Mimosa hostilis  root bark.

The DMT was delivered by smoked inhalation (vaporization). The rapid onset (10-20 sec), short acting  (5-15 min.), and reversible nature of the effects made such a QEEG study feasible. DMT dosage was adjusted to elicit an effective psychedelic experience (ca. 20-30 mg for N,N-DMT; 2-5 mg for synthetic 5-MeO-DMT, and 30-40 mg for the Bufo 5-MeO-DMT material). Healthy volunteers (age 25-60; N=15 men, N=8 women) were tested.

 The protocol consisted of:  5-10 min. baseline control (resting eyes closed) was first acquired, followed by the DMT test condition, usually lasting 5-15 min. When subjects recovered from the DMT induced altered state, a report of their subjective experience was recorded on video and a post recovery  EEG reading was made typically at 15-30 min. A statistical comparison (paired t-tests, correlated samples) of absolute power values for all EEG bands  between baseline vs. DMT tests and post recovery conditions was carried out for all subjects. The DMT- induced profound alterations in consciousness  were tracked with the shifts in the QEEG metrics analysed. The time course and intensity of the subjective experience correlated with the magnitude of the observed EEG effects.

The most consistent effect was a robust suppression of Alpha, obtained for both N,N-DMT and 5-MeO-DMT (Alpha decreased ave. 72%, N=6). During recovery, some subjects showed Alpha rebound increased power at 15-25 min. post DMT (ave. 43% incr., P<.0107, N=9) . A DMT induced reversible shift in FFT spectra from Alpha to Theta was recorded in some subjects. Also, very signifcant  hypercoherence  in all bands (especially Beta) was measured in most subjects.  Gamma power (35-40 Hz) was also increased in some subjects. During post DMT Alpha rebound, subjects reported "being in peace, a calmed  state of wellbeing and clarity". The significance of these findings is discussed with reference to DMT receptor pharmacology mechanisms  and  recent psychedelic brain imaging studies.