Drinking Ayahuasca, a South American hallucinogenic beverage, produces an experimental psychosis that mirrors the pathologic transmethylation theory of schizophrenia. This theory proposes that reduced monoamine oxidase (MAO) activity leads to accumulation of methylated indolealkylamines like bufotenin, DMT, and 5-MeO-DMT, which are strong hallucinogens. Ayahuasca is prepared by boiling plants containing beta-carbolines (potent MAO inhibitors) and DMT, mimicking the biochemical conditions hypothesized in psychoses. After healthy subjects consumed the beverage, urine samples contained the same hallucinogenic compounds found in acute psychotic unmedicated patients. The study also reports the beverage's chemical composition and plant material, along with psychometric and neuroendocrine parameters.
The transmethylation hypothesis of schizophrenia proposes that an inborn error of metabolism causes serotonin or tryptamine to gain extra methyl groups, forming hallucinogenic methylated indolealkyalamines (MIAs) such as bufotenin and DMT. Studies examining MIA excretion in psychotic patients and controls have yielded contradictory results: some show elevated levels in patients with schizophrenia, others do not. The hallucinogenic brew ayahuasca may model how such compounds produce psychotic symptoms. Certain perceptual disturbances in schizophrenia could contribute to deterioration and negative symptoms. Further research into MIA neurophysiology and their role in psychoses is needed.