The impact of ayahuasca on suicidality: results from a randomized controlled trial - Zeifman, Richard J.; Palhano-Fontes, Fernanda; Hallak, Jaime Eduardo Cecilio; Arcoverde, Emerson; Maia-Oliveira, João Paulo; Araujo, Draulio B. (Frontiers in Pharmacology, 2019)