Switch to mania after ayahuasca consumption in a man with bipolar disorder: a case report

Introduction

Ayahuasca is a psychotropic, hallucinogenic Amazonian brew most commonly prepared from Banisteriopsis caapi and Psychotria viridis. The B. caapi component contains β-carbolines (harmine, tetrahydroharmine, and to a lesser extent harmaline and related alkaloids) that act as reversible, selective MAO-A inhibitors, while P. viridis supplies the tryptamine N,N-dimethyltryptamine (DMT). Because DMT is normally inactivated by intestinal MAO-A, its oral psychoactivity depends on co‑administration with MAO-A inhibitors, and some β-carbolines have also been implicated in serotonergic modulation and possible antidepressant actions. This paper presents a single case report of a man with a history suggestive of bipolar spectrum illness who developed a manic episode with psychotic features in temporal relation to participation in a multi‑day ayahuasca ritual. The authors use the case to examine diagnostic implications in the psychiatric setting, consider pharmacodynamic mechanisms that might precipitate a mood switch, and highlight gaps in the literature regarding ayahuasca’s effects in people with mood disorders.