Dear study participant,

Thank you for your interest in taking part in our online survey! Below, we would like to give you some information about the study and the data collected.

Please note that the questionnaire is best completed on a larger screen with a keyboard (computer, laptop). If you are using a smartphone, please rotate the view to landscape format.

What is the study about?

Some people report that they sometimes (re-)experience the effects of psychedelic substances days, weeks, months, or even years after taking them, without having taken psychedelics again.

This can include, for example, the following:

• Reliving previous psychedelic experiences or parts of them (e.g., recurrence, re-experiencing, or flashbacks)
• Psychedelic experiences that you have not experienced before, but which strongly remind you of the psychedelic state in general
• Persistent psychedelic effects or experiences that have not completely subsided after a previous experience with psychedelics (i.e., persistence of individual psychedelic experiences after the acute substance effect has clearly subsided)

With our survey, we would like to help answer the following questions:

• What exactly do psychedelic experiences look like that occur without the acute or immediate influence of a psychedelic substance?
• What are potential factors that contribute to psychedelic experiences occurring in people without (immediate) prior use of psychedelics?
• What factors could be contributing to people suffering from these experiences?
• What is perceived as helpful in dealing with psychedelic (re-)experiencing without (immediate) prior use of psychedelics?

To answer these questions, you will be asked to recall specific psychedelic experiences as accurately as possible.

Important: Anyone who has ever taken psychedelics can take part in this study, regardless of whether or not they have subsequently had psychedelic (re-)experiences.

How long does participation take and what do I get out of it?

Participation in the survey will take about 15-20 minutes. Participation is voluntary and you can stop filling out the questionnaire at any time by closing your browser window. The questionnaire completed up to this point is saved and may be included in the overall evaluation. Your participation will not result in any direct benefit for you. By sharing your experiences, you are making an important contribution to research on the effects of psychedelic substances.

Is participation anonymous?

Participation in the survey is completely anonymous, and your IP address will not be stored. 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 has completed the questionnaire. The study is approved by the Ethics Committee of the Institute of Psychology at the Humboldt University of Berlin (EK 2024-44-k).

Who can take part in the study?
Anyone who fulfills the following requirements can take part in this study:

• You are at least 18 years old
• You have taken a classic psychedelic substance at least once in your life (e.g., psilocybin "magic mushrooms", LSD, mescaline, DMT, ayahuasca, 5-MeO-DMT) or MDMA/ecstasy or ketamine
• You can read and write in German or English

Are there any risks associated with participating in the study?

There are no known risks associated with completing the questionnaire.

Whom can I contact if I need help for distressing (re-)experiences after taking psychedelics?

Unfortunately, we cannot offer you treatment for persistent symptoms as part of the study. However, on our study homepage (www.psychedelicflashbacksurvey.info) you will find information and links to help services that you can turn to.

Information on Data Usage and Data Protection

Responsible Entity

Dr. Ricarda Evens
Humboldt-Universität zu Berlin (Germany)
Faculty of Life Sciences
Institute of Psychology
Chair of Psychotherapy
Unter den Linden 6
10099 Berlin
Phone: +49(0)30 2093 4936
Email: ricarda.evens@hu-berlin.de

Legal Basis

We operate based on the Declaration of Helsinki (World Medical Association's statement on ethical principles for medical research involving human subjects) and the Guideline for Good Clinical Practice. We adhere to the recommendations of the German Research Foundation (DFG) for ensuring good scientific practice.

Storage and Access

The data is stored on servers of the survey platform SoSci Survey GmbH and on servers of Humboldt-Universität zu Berlin in a completely anonymized manner, without any reference to your personal identity. Only study personnel have direct access to this data.

Publication

The publication of research results in publications or at conferences occurs exclusively in anonymized form, ensuring that you, as an individual, cannot be identified. Extracts of your free-text responses may be used as direct quotes in publications; however, these quotes will be selected to prevent any identification of your person.

Storage Duration and Secondary Use

The data exists solely in anonymized form. Please note that individual anonymized data records cannot be deleted on request, as no link can be established between the data and the person. A deletion date for the entire data record is not provided. Following the recommendations of the German Research Foundation (DFG) and the German Psychological Society (DGPs) for quality assurance in research, research data should, if possible, be shared with other researchers. This means that the anonymized data set can be made available to other scientists for further studies.

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: ricarda.evens@hu-berlin.de).