Ricarda Evens, PhD

Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin Berlin, Germany

The Afterglow Inventory (AGI) – a new instrument to measure subacute effects of the psychedelic experience


In contrast to most classic psychiatric drugs, therapeutic effects of serotonergic hallucinogens are discussed to be not merely driven by acute psycho-physiological drug effects but also by transient subacute changes of perception, mood, and cognition. Those subacute effects may last up from hours to several weeks after the acute psychedelic experience. They have been described as a state characterized by “release of guilt feelings”, “brighter mood”, “peace of mind”, “intense interpersonal closeness”, and in which “life and death can be looked at from a new perspective” (Pahnke 1969). With respect to a largely positive reception of those subacute effects they have also been termed “afterglow” effects and might offer a window of increased responsiveness to therapeutic interventions. Despite a huge number of individual experience reports, no standardized instrument to measure subacute effects of the psychedelic experience is available yet. In the poster a newly developed instrument to measure the afterglow phenomenon will be presented.

The questionnaire was created in a three-step process: First, using a theory-driven approach, existing concepts of the “afterglow” were reviewed, and an initial set of questions was designed. Second, item population was extended and refined using expert feedback. Third, final item selection was based on item quality data and their ability to discriminate between psychedelic and non-psychedelic subacute drug effects in an online survey. Data on reliability and validity will be presented and potential applications will be discussed.


Ricarda Evens is a psychologist and psychotherapist. She received her PhD from the University of Dresden (Germany) investigating the interaction of disease and treatment effects in the development of cognitive symptoms in Parkinson’s disease. Her current research is concerned with the further development of psychedelic-assisted psychotherapy. As a CBT-trained psychotherapist she works with patients suffering from trauma related, anxiety, and obsessive-compulsive disorders.



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