Study on traumatic experiences related to psychedelics

What is the study about?

Psychedelics such as LSD, Psilocybin/Magic Mushrooms, DMT, 5-MeO-DMT, Ayahuasca, Mescaline, or similar substances can have various effects on consciousness. Numerous clinical studies have observed positive effects of these substances on mental health conditions such as depressive and anxiety disorders. Such promising results have sparked increased interest in using psychedelics clinically.

Despite the positive effects observed in clinical studies, there are also reports of challenging experiences with the use of psychedelics. This survey focuses particularly on any challenging or traumatic experiences with psychedelics, the aftermath of which continued to burden you even after the acute effects of the substance had subsided. We want to learn more about your experience with psychedelics, how you felt in the weeks and months after, and what was or wasn’t helpful in managing any lingering challenges. Please note that the study does not focus on experiences related to self-treatment of pre-existing trauma with psychedelics.

How long does participation take and what do I gain from it?

The survey will take about ~35 minutes to complete. Participation is voluntary, and you can cancel filling out the questionnaire at any time by closing your browser window. There is no direct benefit to you from participating. Your participation, through sharing your experiences, provides a significant contribution to research on psychedelic substances effects.

Is participation anonymous?

Your participation in this survey is completely anonymous and we do not store any IP addresses. At the beginning of the questionnaire, we will ask for some personal data, such as age and gender. However, with this information, it is not possible to trace who filled out the questionnaire. This study is approved by the Ethics Committee of the Institute of Psychology at Humboldt-Universität zu Berlin (Germany) (2024-07R1).

Who can participate in the study?

Anyone who meets the following criteria can participate in this study:

  • You are at least 18 years old.
  • You have taken a psychedelic substance at least once in your life (e.g., classic psychedelics like psilocybin/Magic Mushrooms, LSD, Ayahuasca, Mescaline, DMT, 5-MeO-DMT, as well as atypical psychedelics like MDMA/Ecstasy, Ketamine, or Cannabis).
  • You are able to read and write in German or English.
  • You have experienced at least one particularly challenging or traumatic experience with psychedelic substances, the aftermath of which continued to burden you even after the acute effects of the substance had subsided. This could include:


  • A very difficult acute experience (e.g., "bad trip").
  • The occurrence of a challenging or traumatic memory during the substance's effects.
  • The occurrence of a threatening event during the substance's effects (e.g., assault, abuse, rape, accident)
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Are there risks associated with study participation?

Filling out the questionnaire involves recalling the challenging psychedelic experiences, which might temporarily intensify unpleasant emotions.

Whom can I contact if I need help with persistent problems after psychedelic substance use?

Unfortunately, within the study, we cannot offer treatment for persistent problems after psychedelic substance use. However, on this homepage you can find information and links to support services that you can reach out to.

Whom can I contact for further questions?
For any questions regarding the study, feel free to contact the principal investigator, Dr. Ricarda Evens, at any time (Email:

Our Team

Dr. Ricarda Evens
Abdo Uyar
Emily Alexandra Gosslau
Franziska Dambeck
Dr. Max Wolff
Dr. med. Dimitris Repantis
Prof. Dr. Ulrike Lüken

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