Peak experiences and the afterglow phenomenon: When and how do therapeutic effects of hallucinogens depend on psychedelic experiences?

Abstract

Interest in the therapeutic potential of psychedelic substances has recently resumed. During an early phase of human psychedelic research, their therapeutic application in different pathologies had been suggested, and the first evidence for efficacy was provided. The range of recent clinical applications of psychedelics spans from cluster headaches and obsessive-compulsive disorder to addiction and the treatment of fear and anxiety in patients suffering from terminal illness, indicating potentially different therapeutic mechanisms. A variety of approaches in psychotherapy emphasize subjective experiences, such as so-called peak experiences or afterglow phenomena, as differentially mediating therapeutic action. This review aims to re-evaluate earlier and recent concepts of how psychedelic substances may exert beneficial effects. After a short outline of neurophenomenological aspects, we discuss different approaches to how psychedelics are used in psychotherapy. Finally, we summarize evidence for the relationship between subjective experiences and therapeutic success. While the distinction between pharmacological and psychological action obviously cannot be clear-cut, they do appear to contribute differently from each other when their effects are compared with regard to pathologies.

In the evidence

This study is part of the evidence base for a synthesis in the library. Here is how each one recorded it.

• State of the evidence: Mystical experience ↕Mixed

  Concludes that pharmacological and psychological actions of psychedelics, including peak experiences and afterglow, appear to contribute differently to therapeutic effects depending on the pathology.

  Synthesized October 25, 2026

Comparable studies

Other narrative reviews on mystical experience, most cited first.