Neuroscience and Biobehavioral Reviews
August 1, 2025
Larry Douglas Fort, Cyril Costines, Marc Wittmann et al.
14 citations
In recent years, there has been a renewed interest in the conceptual and empirical study of altered states of consciousness (ASCs), induced pharmacologically or otherwise, driven by their potential clinical applications. To draw attention to the rich history of research in this domain, we review prominent classification schemes that have been proposed to introduce systematicity into the...
Journal of Psychopharmacology
March 31, 2025
Tomislav Majić, Timo Torsten Schmidt, Anna Gröticke et al.
4 citations
Background: Classic psychedelics such as psilocybin and lysergic acid diethylamide are anecdotally associated with the phenomenon of “psychedelic afterglow,” a set of predominantly pleasant, temporary psychological effects reported after the acute effects have subsided. Since post-acute effects are crucial for the therapeutic use of psychedelics, an instrument to systematically assess subacute...
Current Topics in Behavioral Neurosciences
December 31, 2024
Cyril Costines, Timo Torsten Schmidt
8 citations
The range of phenomena that can be induced by psychedelic substances is broad and variable, including effects on perception, cognition, and emotion. The umbrella term "psychedelic phenomenology" is used to refer to a combination of altered experiential features, such as hallucinations or ego dissolution, which together constitute a psychedelic experience. However, there is no consensus on the...
May 3, 2024
Kasey Devitt, Johanna Prugger, Tim Hirschfeld et al.
preprint
The open data initiative Altered States Database (ASDB) collects psychometric questionnaire data on the subjective experiences of pharmacologically and non-pharmacologically induced altered states of consciousness. The ASDB is updated yearly and can be utilized by both researchers and non-scientists to access information or undertake further work on the data. The current update adds data...
Frontiers in Psychology
February 14, 2024
Caspar Montgomery, Timo Torsten Schmidt, Ioanna Amaya
13 citations
Flicker light stimulation (FLS) is a non-pharmacological method of inducing altered states of consciousness (ASCs), producing hallucination-like phenomena as well as effects extending beyond the visual modality, including emotional effects. Research into the psychological and neural mechanisms of FLS is still in its infancy, but can be informed by research into other methods of inducing ASCs....
June 4, 2023
Timo Torsten Schmidt, Cyril Costines, Enzo Tagliazucchi et al.
2 citations
preprint
The Altered Xperience Project (AXP) is an ongoing research project that takes the form of an open citizen science initiative. Its main goal is to systematically collect and consolidate data on the subjective experiences induced by various consciousness-manipulating techniques (CMTs). These include both psychoactive substances as well as non-pharmacological manoeuvres that induce altered states...
February 22, 2023
Madlen Peters, Johanna Prugger, Petar Radoev Dimkov et al.
3 citations
preprint
The Altered States Database (ASDB) is an open science project, containing psychometric questionnaire data on altered states of consciousness experiences induced by diverse means. The database was first described in: Schmidt, T. T., & Berkemeyer, H. (2018). The Altered States Database: Psychometric Data of Altered States of Consciousness. In Front. Psychol. and an upgrade to cohere to the...
Therapeutic Advances in Psychopharmacology
2023
Ricarda Evens, Tomislav Majić, Timo Torsten Schmidt et al.
49 citations
Background: Classic serotonergic psychedelics have anecdotally been reported to show a characteristic pattern of subacute effects that persist after the acute effects of the substance have subsided. These transient effects, sometimes labeled as the ‘psychedelic afterglow’, have been suggested to be associated with enhanced effectiveness of psychotherapeutic interventions in the subacute period....
PLoS One
March 16, 2022
Katharina Dworatzyk, Tallulah Jansen, Timo Torsten Schmidt
19 citations
Several measures have been designed to assess subjective experiences induced by psychedelic substances or other mind-altering drugs as well as non-pharmacological methods. Recently, two self-report questionnaires have been introduced to measure acute adverse effects following psilocybin ingestion and the phenomenon of ego-dissolution associated with the use of psychedelics, respectively. The...
PLoS One
July 1, 2021
Marie Therese Bartossek, Johanna Kemmerer, Timo Torsten Schmidt
43 citations
Flicker light stimulation can induce short-term alterations in consciousness including hallucinatory color perception and geometric patterns. In the study at hand, the subjective experiences during 3 Hz and 10 Hz stroboscopic light stimulation of the closed eyes were assessed. In a within-subjects design (N = 24), we applied the Positive and Negative Affect Schedule (mood state), time...
April 2, 2021
Katharina Dworatzyk, Tallulah Jansen, Timo Torsten Schmidt
3 citations
preprint
Several measures have been designed to assess subjective experiences induced by psychedelic substances and other mind-altering drugs or non-pharmacological methods. Recently, two self-report questionnaires have been introduced to measure acute adverse effects following psilocybin ingestion and the phenomenon of ego-dissolution associated with psychedelic use, respectively. The 26-item...
Journal of Psychopharmacology
March 4, 2021
Tomislav Majić, Meike Sauter, Felix Bermpohl et al.
14 citations
Background/aim: Kambô is a name for the secretion of the Giant Maki Frog ( Phyllomedusa bicolor), which has been used by indigenous cultures from the Amazonas basin and has recently become popular in alternative healing circles in Western countries, with a certain overlap with psychedelic self-exploration. Methods: We carried out an online-based survey in English (54.92%) and German...
Scientific Reports
December 9, 2020
Timo Torsten Schmidt, Simon Reiche, Caroline L. C. Hage et al.
12 citations
Kambô, the secretion of the Amazonian Giant Leaf Frog (Phyllomedusa bicolor) contains a plethora of bioactive peptides and was originally used by indigenous communities from the Amazon basin as medicine for improving hunting capacities. In the last 20 years, Kambô has spread to Western urban healing circles. To date it is still controversial whether the acute effects of Kambô include...
Scientific Reports
October 29, 2020
Timo Torsten Schmidt, Nisha Jagannathan, Michal Ljubljanac et al.
Different pharmacologic agents have been used to investigate the neuronal underpinnings of alterations in consciousness states, such as psychedelic substances. Special attention has been drawn to the role of thalamic filtering of cortical input. Here, we investigate the neuronal mechanisms underlying an altered state of consciousness (ASC) induced by a non-pharmacological procedure. During fMRI...
bioRxiv (Cold Spring Harbor Laboratory)
July 24, 2020
Timo Torsten Schmidt, Simon Reiche, Caroline L. C. Hage et al.
preprint
ABSTRACT Kambô is the name for the secretion of the Giant Leaf Frog (Phyllomedusa bicolor) containing a plethora of bioactive peptides. Originally, it is ritually used by different ethnicities from the Amazon basin as a remedy against bad luck in hunting. In the last twenty years, Kambô has spread to Western urban centers, often associated with the use of ayahuasca. Anecdotal reports claim...
bioRxiv (Cold Spring Harbor Laboratory)
June 11, 2020
Tim Hirschfeld, Timo Torsten Schmidt
8 citations
preprint
Abstract Psilocybin is the active component of magic mushrooms and is well known for its psychoactive properties. Different questionnaires have been developed to systematically quantify altered states of consciousness induced by psychoactive drugs. The aim of this study was to obtain the dose-response relationships of the subjective experiences induced by psilocybin in healthy study...
Frontiers in Psychology
July 2, 2018
Timo Torsten Schmidt, Hendrik Berkemeyer
75 citations
The experimental induction of altered states of consciousness (ASC) constitutes a research opportunity to relate changes in phenomenological states to underlying biophysical mechanisms. A variety of pharmacological and non-pharmacological methods were reported to induce consciousness alterations in humans, ranging from the consumption of psychoactive drugs to special breathing techniques or...
Fortschritte der Neurologie · Psychiatrie
July 1, 2017
Tomislav Majić, Henrik Jungaberle, Timo Torsten Schmidt et al.
10 citations
Zusammenfassung Hintergrund Der Einsatz von serotonergen Halluzinogenen (Psychedelika) wie Lysergsäure-Diethylamid (LSD) und Psilocybin und Entaktogenen wie 3,4-Methylendioxymethamphetamin (MDMA) im Rahmen von Psychotherapie ist in den letzten Jahren wieder zunehmend ins Licht des wissenschaftlichen Interesses gerückt. Die vorliegende Arbeit fasst die aktuelle Evidenz zur substanzunterstützten...