I owe for the revision of manuscript. To Ing. Nahanga Verter, Ph.D. for proofreading of the translation.From foreign colleagues, I thank to Nuria Romo Avilés, Ph.D., as she inspired me to write a chapter on the legal aspects of the ayahuasca use, and to Alfonso Marquina Márquez, Ph.D., for the consultation of chapters on religion and spirituality.In conclusion, I thank all my informants for their helpful participation in the research, and especially my family for permanent support in my work.