Ebook: Long-term effects of psychedelic drugs: A systematic review

Research into the basic effects and therapeutic applications of psychedelic drugs has grown considerably in
recent years. Yet, pressing questions remain regarding the substances’ lasting effects. Although individual studies
have begun monitoring sustained changes, no study to-date has synthesized this information. Therefore, this
systematic review aims to fill this important gap in the literature by synthesizing results from 34 contemporary
experimental studies which included classic psychedelics, human subjects, and follow-up latencies of at least two
weeks. The bulk of this work was published in the last five years, with psilocybin being the most frequently
administered drug. Enduring changes in personality/attitudes, depression, spirituality, anxiety, wellbeing,
substance misuse, meditative practices, and mindfulness were documented. Mystical experiences, connectedness, emotional breakthrough, and increased neural entropy were related to these long-term changes in psychological functioning. Finally, with proper screening, preparation, supervision, and integration, limited aversive side effects were noted by study participants. Future researchers should focus on including larger and more
diverse samples, lengthier longitudinal designs, stronger control conditions, and standardized dosages.