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