Ayahuasca, the Psychedelic Antidepressant?

A traditional Amazonian psychedelic brew is an effective and rapid-acting antidepressant, according to a paper just published. But the new study revives some long-standing questions. Ayahuasca is a mixture of herbs, traditionally used for spiritual and therapeutic purposes. The main active ingredients are N,N-DMT, a potent psychedelic, and several molecules that inhibit the enzyme MAO. The MAO inhibitors serve to prevent the N,N-DMT from being broken down by the digestive system, allowing it to enter the bloodstream and cause hallucinations and other alterations of consciousness. In the present study, Brazilian researchers Fernanda Palhano-Fontes and colleagues gave ayahuasca to 14 patients with chronic depression who hadn't responded to other antidepressants. Another 15 depressed patients received a placebo drink. The ayahuasca group showed a strong improvement in their depressive symptoms, which persisted for at least a week (the last assessment was on day 7). The patients given placebo also improved but this effect was modest and short-lived. This graph shows the MADRS depression scale scores during the trial (lower is better):