Unifying Theories of Psychedelic Drug Effects.
How do psychedelic drugs produce their characteristic range of acute effects in perception, emotion, cognition, and sense of self How do these effects relate to the clinical efficacy of psychedelic-assisted therapies Efforts to understand psychedelic phenomena date back more than a century in Western science. In this article I review theories of psychedelic drug effects and highlight key concepts which have endured over the last 125 years of psychedelic science. First, I describe the subjective phenomenology of acute psychedelic effects using the best available data. Next, I review late 19th-century and early 20th-century theories-