This paper describes the protocol for the Ayahuasca Treatment Outcome Project (ATOP), which evaluates addiction treatment services at the Takiwasi Center in the Peruvian Amazon. The project aims to assess outcomes and understand therapeutic mechanisms of an ayahuasca-assisted, integrative treatment model for addiction rehabilitation. The protocol emphasizes the importance of treatment setting in designing and delivering a program involving the psychedelic tea ayahuasca. A mixed-methods approach to data collection and analysis is used to understand why, how, and for whom the treatment is effective across various outcomes.
One year after completing an ayahuasca-assisted, integrative addiction treatment program at the Takiwasi Centre in Peru, 52 participants showed significant reductions in alcohol and drug use severity, depression, and anxiety, and improvements in some quality-of-life dimensions. The majority rated all program aspects as important, particularly the spiritual and therapeutic significance of the ayahuasca experience. However, there was considerable individual variation in outcomes and treatment duration. Within the limitations of an uncontrolled observational study, the findings suggest promise for ayahuasca's effectiveness in a multifactorial treatment context for individuals with significant treatment histories, high comorbidity, and treatment motivation.