A review of nine small clinical trials found that ayahuasca and psilocybin, when used to treat major depressive disorder and treatment-resistant depression, are associated with changes in several biological markers. These include increased serum brain-derived neurotrophic factor, decreased serum C-reactive protein, altered amygdala activation, and changes in functional connectivity between brain regions such as the ventromedial prefrontal cortex, anterior cingulate cortex, and posterior cingulate cortex. These associations suggest potential mechanisms of clinical response, but larger, longer-term studies are needed to confirm these findings.
Psychedelic compounds have been used by humans for millennia, originally derived from plants and fungi by ancient and indigenous peoples. Western society was reintroduced to them in the mid-20th century, first through Albert Hofmann's synthesis of LSD in the 1940s and then through Gordon Wasson's introduction to psilocybin mushrooms by Maria Sabina in the 1950s. These substances became subjects of scientific and cultural interest, but their prominence declined sharply in the 1970s due to international drug laws. A resurgence began in the 1990s, leading to an ongoing renaissance in psychedelic science.