Research Poster 2025

Landscape Analysis of Pre-Registered Clinical Trials involving Classical Psychedelics

Psychedelic clinical research is expanding rapidly. Providing an up-to-date overview of the current research landscape, trends in trial registrations, and study designs is essential for guiding future research. This review aims at systematically analysing the current state and trends in psychedelic clinical trial registrations. A systematic search of ClinicalTrials.gov was conducted on November 11, 2024, to identify all interventional psychedelic clinical trials. All registered interventional trials investigating (therapeutic) effects of classical serotonergic psychedelics (e.g., LSD, psilocybin, DMT, 5-MeO-DMT, mescaline) were included. Data were downloaded directly or extracted by two researchers. Data analysis included a negative binomial regression to assess time trends and descriptive summaries of study characteristics. Outcomes included trial registration trends, substance distribution, study phase progression, sample and trial characteristics, geographical distribution, and psychotherapy reporting practices. A total of 241 trials were identified, with an exponential rise in registrations since 2006 and a marked acceleration post-2019. Two-thirds of trials are ongoing or planned. Psilocybin remains the most frequently studied substance and is most advanced towards clinical approval, but short-acting psychedelics (DMT, 5-MeO-DMT) have recently been introduced with a more focused clinical scope. Industry involvement is increasing, though university-led research still dominates. Reports of psychotherapy components numerically increased following 2023 FDA recommendations, though no substantive changes in quality of descriptions of applied interventions were observed.

LYTA Trial Protocol: LSD-Assisted Therapy for Alcohol Use Disorder

Our clinical research group for substance-assisted therapy at the UPK Basel includes professionals from the fields of psychiatry, psychology, and clinical research. The main focus of our work is research on the effects of LSD, which we have been studying since 2014 in several studies. We examine efficacy, safety and possible positive long-term effects of LSD in mental health conditions such as anxiety and depression. In the LYTA trial, together with the University of Bern, we will investigate LSD assisted therapy for alcohol use disorder in a multicenter, double-blind, randomized, active-placebo controlled phase II neuroimaging trial with a consecutive open-label phase.

Dr. Andre Ihlenfeld

Copeia GmbH, Bergisch Gladbach, Germany D-51469

DMT Reshapes Spontaneous Brain Activity

Altered states of consciousness and disorders of consciousness are valuable tools for studying consciousness. By examining changes in brain activity during states like anesthesia, where consciousness is lost, or psychedelic experiences, where perception and cognition are profoundly altered, we gain insights into the nature of human consciousness. We used the NeuroSynth database of meta-analytic cognitive maps to extract cognitive matching scores from participants at resting-state and under DMT. Cognitive matching scores refer to the ability to decode cognitive processes from an fMRI time series. Can we decode cognitive matching scores at rest? If yes, does DMT affect this spontaneous brain activity? Do these results correlate to the DMT subjective experience? Here, we explore NeuroSynth as a potential tool for neurophenomenology, allowing us to translate fMRI BOLD activity to cognition and subjective experience.

A Mixed-Methods Analysis of Psychedelic-Augmented Meditation Experiences: Qualitative Insights from a RCT in a Mindfulness Retreat Setting 

The acute subjective effects (ASE) of psychedelic substances are assumed to play a critical role for their therapeutic and well-being enhancing benefits. However, recent work voiced critique regarding the validity, and adequacy of conventional measures and modalities utilized to study ASEs of psychedelics, and call for data-driven, unbiased, and experience-based research approaches. The emergence of advanced Natural Language Processing techniques as an enabler of data-driven qualitative research holds promise for addressing the current biases and limitations in the investigation of ASEs of psychedelics. In the present study, we employed an NLP-driven, multi-method analytical paradigm to study the subjective experiences of participants in an ecologically valid RCT examining the effect of DMT/harmine on meditative states in experienced meditators using phenomenological interviews. Our analysis showed differences in the thematic landscape and experiential diversity of meditation under placebo and meditation under DMT-harmine while showing overlap in their semantic topographies. 

Risks and Benefits associated with fast-paced Breathwork: Results of an Online-Survey

Fast-paced breathwork as a non-pharmacological method for the induction of altered states of consciousness is receiving increasing public attention. However, scientific evidence regarding the effects of breathwork remains limited. Little is known about the contextual factors that drive beneficial change, as well as the potential risks associated with the practice. To address this gap, we conducted an online survey (n = 379) assessing participants’ most recent breathwork experience. Key variables included setting, information and instructions provided, the use of touch, adverse events, and perceived outcomes. Most participants described their experience as pleasant and overall beneficial and believed that it led to a lasting improvement in their sense of wellbeing. However, a range of physiological and psychological side effects were also reported. These included muscle cramps, tension and restlessness, feeling down, sad or hopeless and experiences of flashbacks or upcoming traumatic events. The experience of side effects was associated with more negative overall outcomes.

Prior communication, the provision of clear information - on the breathing technique, expected effects and integration strategies - emotional and physical safety, perceived support as well as sufficient integration were all correlated with improvements in wellbeing. Touch that was experienced as helpful and aligned with prior consent was associated with beneficial outcomes, whereas touch perceived as intrusive was linked to negative outcomes. 

Ayahuasca's Impact on Veterans with PTSD in a Traditional Framework – Insights from a 6-Month Follow-up Study

Onaya Science has conducted research on the mental health impact of traditional Shipibo-led ayahuasca ceremonies since 2016, including multi-modal investigations with military veterans diagnosed with PTSD.

This poster presents preliminary six-month follow-up findings involving 42 veterans with PTSD (target sample 210 by 2027) who participated in Shipibo-led ayahuasca ceremonies in an adapted traditional framework. Participants showed significant reductions in PTSD symptoms, depression, and anxiety, along with improved life satisfaction at six-month follow-up. EEG results indicated neural changes consistent with enhanced cortical flexibility and adaptive regulation. Epigenetic analysis is now underway, along with full microbiome profiling, to further characterise the biological effects of ayahuasca treatment. Control group (treatment as usual) is also being collected now. 

These findings highlight the multi-systemic potential of traditional ayahuasca practices and reinforce the need for rigorous, reciprocal partnerships with Indigenous healers—recognising these traditions as long standing systems of healing that merit scientific validation and ethical collaboration.

Control Group Outcomes in Trials of Psilocybin, SSRIs, or Esketamine for Depression

Together with my team at Karolinska Institutet, I am currently working on the CAPSI study, a randomized clinical trial investigating psilocybin for cancer-related depression, where we also explore brain changes using multimodal imaging techniques. My research interests include the biological mechanisms underlying psilocybin’s antidepressant effects and depression more broadly, as well as the role of psychological factors such as expectancy, blinding, and the therapeutic context in shaping treatment outcomes. At this conference, I will present our meta-analysis examining control group outcomes in psilocybin trials compared to other antidepressant trials, where our findings may have important implications for how we interpret treatment effects in psychedelic research and for the design of future clinical trials.

Association Between Psychological Therapy Quantity and Depressive Symptom Reduction in Psychedelic-Assisted Therapy: A Systematic Review and Meta-Analysis

Depression is a leading cause of global disease burden, and many patients do not achieve adequate relief from existing pharmacological or psychotherapeutic treatments. Psychedelic-assisted therapy (PAT), which combines serotonergic psychedelics such as psilocybin or LSD with psychological support, has re-emerged as a promising intervention. While trials consistently demonstrate large reductions in depressive symptoms, the therapeutic protocols used in PAT almost universally include preparatory and integration sessions, yet the specific contribution and necessity of these components to treatment outcomes remains unclear.

To address this gap, we conducted a systematic review and multilevel meta-analysis of 12 controlled trials including 733 participants with depressive symptoms. Across studies, PAT was associated with a large and robust reduction in depressive symptoms compared to control conditions. Importantly, more hours spent on preparation prior to dosing was significantly associated with larger symptom reduction, whereas hours of integration, number of sessions, and overall treatment duration showed no significant associations. These findings suggest that preparation may play a key role in optimizing outcomes. This association could be explained by a strengthening of the therapeutic alliance, clarifying treatment intentions, reducing anxiety, and fostering psychological readiness for the psychedelic experience. Nonetheless, the evidence base remains limited by heterogeneous protocols, small study numbers, and high risk of bias. Further research is needed to clarify the role of therapy components and inform evidence-based standards for PAT.

A Research Agenda on Psychedelic-Assisted Therapy Discourse on Social Media 

By bridging communication studies and clinical psychedelic research, this work highlights the need for a transdisciplinary approach to understand how digital conversations shape expectations, treatment decisions, and public perceptions of psychedelic-assisted therapy.

This research agenda aims to systematically examine psychedelic-assisted therapy discourse on social media. While such platforms provide valuable spaces for information exchange, much of the shared content is anecdotal and may conflict with emerging scientific evidence, complicating users’ ability to make informed health decisions. We outline key five research directions: 1) analyzing social media narratives, 2) mapping cross-platform discourse, 3) investigating users’ motivations and information-seeking practices, 4) examining implications for clinical practice, and 5) addressing ethical concerns.

Beyond outlining these directions, this work seeks to gather feedback from clinicians and researchers with expertise in psychedelic-assisted therapy to help guide further development of this line of inquiry.

Clinical Real-World Outcomes of Psilocybin Treatment for Treatment-Resistant Depression

At the Second Opinion Depression Consultation Service of the Psychiatric University Hospital Zürich (PUK Zürich), we specialize in the treatment of complex and treatment-resistant depression (TRD). Within the consultation, we employ novel diagnostic tools and highly specialized treatment strategies. In this ongoing project, we explore the application of psilocybin in real-world psychiatric care for patients not responding to conventional antidepressant treatment. Specifically, we examined the clinical outcomes of 19 patients with TRD who underwent up to four flexibly scheduled psilocybin sessions at PUK Zürich between 2023 and 2025. In this study, we found a significant and clinically relevant decrease in depressive symptoms at the end of treatment. Further, no additive benefit of multiple psilocybin sessions was detected. Instead, they appear to sustain the initial improvement. Although the effects observed in this study are smaller in magnitude, the overall results align with findings from randomized controlled trials. We thus provide important insights into treatment efficacy in early clinical practice. Larger prospective trials are now needed to further explore the feasibility of psilocybin treatment in psychiatric care.

Mapping Psychedelic Use and Mystical Experience Across Menstrual Cycle

Women’s biology remains largely overlooked in psychedelic research, although hormonal fluctuations across the menstrual cycle can influence mood, perception, and emotional processing. This study explores how menstrual cycle phase and hormonal contraceptive use may shape the intensity and quality of psychedelic experiences.

Fifty-two participants (31 naturally cycling, 21 using hormonal contraceptives) completed an online survey including the Mystical Experience Questionnaire (MEQ). Menstrual phases were coded based on self-reported cycle day.

Results showed a significant higher Positive Mood scores in the mid-luteal phase compared to the periovulatory phase, while other MEQ subscales showed moderate but nonsignificant effects. Hormonal contraceptive users reported higher and more stable MEQ scores than naturally cycling participants, with reduced variability across subscales.

These preliminary findings suggest that menstrual phase and contraceptive status may both influence the subjective quality and variability of psychedelic experiences, underscoring the importance of integrating hormonal factors into future psychedelic research.

Circular Breathwork vs Progressive Muscle Relaxation: A Randomised Controlled Trial on Trauma Processing and Well-Being

Childhood trauma affects up to 70% of the population and leads to rigid emotional and cognitive processing patterns that narrow perception and impair well-being. These effects are deeply embodied, reflected in alterations of the autonomic nervous system, HPA axis, and brain activity. Circular breathwork, a technique that induces altered states of consciousness, may offer an accessible means to address these physiological and psychological imprints. However, rigorous, controlled evidence on its efficacy and mechanisms is still lacking.

This randomized controlled trial compares circular breathwork with progressive muscle relaxation (PMR) to examine its long-term effects on trauma processing and socio-emotional functioning. We hypothesize that circular breathwork will (1) reduce depressive and anxiety symptoms and enhance well-being; (2) increase social trust and reduce threat sensitivity and experiential avoidance; (3) modulate neuronal activity linked to socio-emotional regulation (EEG); (4) modulate stress-related systems, including cortisol (hair, saliva), HRV, heart rate, and sleep; and (5) explore immune markers of stress and inflammation.

The project aims to generate the first evidence-based treatment protocol for circular breathwork in individuals with childhood trauma, openly sharing psychological, physiological, and neural findings. This will provide safe, low-cost tools to support trauma recovery and promote well-being in both clinical and community settings.