This post is part of a Nature Blog Focus on hallucinogenic drugs in medicine and mental health, inspired by a recent Nature Reviews Neuroscience paper ‘The neurobiology of psychedelic drugs: implications for the treatment of mood disorders’ by Franz Vollenweider and Michael Kometer.
This article will be available, open-access, until September 23. For more information on this Blog Focus please visit the Table of Contents.
In a hut, in a forest, in the mountains of Colombia, I am puking into a bucket. I close my eyes and every time my body convulses I see ripples in a lattice of multi-coloured hexagons that flows out to the edges of the universe.
Two hours earlier, I had swallowed a muddy brown brew known as yagé, famous for its hallucinogenic effects, its foul taste, and the accompanying waves of nausea that eventually lead to uncontrollable vomiting.
Yagé has been used for hundreds, if not thousands, of years – not as a recreational drug – but as a psychological and spiritual aid that holds a central place in indigenous religion.
Romualdo, a displaced Witoto shaman who led the ceremony, was convinced of its mental health benefits and had confidentially assured me that, after the puking, I would remain in a state of heightened conciencia where I could “ask questions, solve difficulties and communicate with spirits.” “Come with a question,” he told me, “you’ll feel better afterwards.”
The main active ingredient in yagé, known outside Colombia as ayahuasca, is dimethyltryptamine or DMT, a hallucinogenic drug from the tryptamine family that works – like LSD and psilocybin – largely through its effect on serotonin receptors.
Psychedelic drugs, mental health and brain science have traditionally made for a heated combination, but a recent scientific article, published in September’s Nature Reviews Neuroscience, has attempted to more coolly assess the growing research on the potential of hallucinogens to treat depression and anxiety.
Lab studies and medical trials form a small but robust body of knowledge that reveal reliable benefits and promising future avenues. The dissociative anaesthetic ketamine has been found to lift mood – even in cases of severe of depression – while psilocybin, present across the world in mushrooms and fungi, has been shown to have anxiety reducing properties.
But while no serious bad reactions have happened during the trials, the full range of potential risks is still not fully understood, meaning the treatments remain firmly in the lab.
The caution is warranted. Psychiatrists are more than aware of hospital admissions triggered by the same drugs taken outside of controlled conditions, and so the compounds will remain as experimental treatments until the risks are fully known.
Nevertheless, the science is now developed enough for new ideas to be generated based solely on a neurobiological understanding of the drugs.
The authors of this latest review, neuroscientists Franz Vollenweider and Michael Kometer, note that success with psychedelics that largely work on the glutamate system – such as ketamine and PCP – may be due to the fact that these circuits regulate long-term brain changes. This suggests a potential path to extending the mood lifting effects of these drugs beyond the initial ‘trip’.
One key advance would be an understanding of how the chemical structure of a particular hallucinogen relates to the experience it creates, allowing researchers a neurological toolkit that could be used to trigger the beneficial effects while toning down the extreme unreality that some people find unpleasant.
Yet, it is still not clear whether such benefits are separable from the psychedelic effects and it may be that the ‘active ingredient’ lies somewhere between an altered state of consciousness and a reflective mind, as some studies on drug-assisted psychotherapy suggest.
It is also clear that a great number of ritual hallucinogens, widely used by indigenous people for their psychological benefits, have yet to be explored.
As my own investigation ends, I leave the isolated hut feeling exhausted and disoriented as the clear morning light refracts through my thoughts and casts bright trickling colours into unfilled spaces.
As Romualdo promised, I feel better, elated even, but the questions I brought remain unanswered and have similarly refracted into a thousand intricate doubts.