In the 1970s, researchers and theoreticians of states of consciousness jointly discussed hypnosis and psychedelic alterations of consciousness, but recent research has mostly kept these topics apart. This paper discusses the similarities and differences of hypnosis and psychedelic alterations of consciousness, stressing that states of consciousness should not be defined by their preceding contexts. Predictors of positive responses to psychedelics (e.g. absorption and openness to experience) also predict hypnotic responsiveness. Most experiential changes (e.g. changes in bodily sensations and image, increased simple and complex imagery, and transcendent phenomena) produced by psychedelics are also reported within minimal suggestion hypnosis by highly responsive participants. Yet, there are differences in single sessions in that, as compared with hypnosis, psychedelic experiences typically last longer, are less controllable but more intense, and might produce more negative outcomes but also have a greater potential for positive long-term effects. Hypnosis, psychedelic research, and clinical work can enrich each other and should be more integrated than has been the case recently.
Keywords: Altered state of consciousness; anomalous experience; hypnosis; psychedelics.