Skip to content

Hannes Kettner

Imperial College London, University of California, San Francisco

63 papers in the library · 3,022 citations · publishing 2018-2026

Papers

Sort Most recent Most cited

Improvements in well-being following naturalistic psychedelic use and underlying mechanisms of change in older adults: A prospective cohort study.

Research Square March 8, 2024 Hannes Kettner, Leor Roseman, Adam Gazzaley et al. 5 citations preprint

Affective symptoms such as anxiety, low mood, and loneliness are prevalent and highly debilitating symptoms among older adults (OA). Serotonergic psychedelics are novel experimental interventions for affective disorders, yet little is known regarding their effects in OA. Using a prospective cohort design, we identified 62 OA (age ≥ 60 years) and 62 matched younger adults (YA) who completed...

Psychiatric risks for worsened mental health after psychedelic use.

Journal of Psychopharmacology March 4, 2024 Alessia Marrocu, Hannes Kettner, Brandon Weiss et al. 51 citations

Background: Resurgent psychedelic research has largely supported the safety and efficacy of psychedelic therapy for the treatment of various psychiatric disorders. As psychedelic use and therapy increase in prevalence, so does the importance of understanding associated risks. Cases of prolonged negative psychological responses to psychedelic therapy seem to be rare; however, studies are limited...

DOI: 10.1177/02698811241232548 (opens in new tab) Full text (opens in new tab) Psychedelic therapy Psychedelic treatment Therapeutic psychedelics Therapeutic promise +16

The Relationship Between Changes in Mindfulness and Subsequent Changes in Well-Being Following Psychedelic Use: Prospective Cohort Study.

JMIR Formative Research March 4, 2024 Grant Jones, Felipe Herrmann, Adam Bear et al. 2 citations

This study demonstrates that changes in mindfulness predict subsequent changes in well-being in a data set including individuals who recently engaged in psychedelic use.

Psychedelics and sexual functioning: a mixed-methods study

Scientific Reports February 7, 2024 Tommaso Barba, Hannes Kettner, Caterina Radu et al. 24 citations

Abstract Do psychedelics affect sexual functioning postacutely? Anecdotal and qualitative evidence suggests they do, but this has never been formally tested. While sexual functioning and satisfaction are generally regarded as an important aspect of human wellbeing, sexual dysfunction is a common symptom of mental health disorders. It is also a common side effect of selective serotonin reuptake...

DOI: 10.1038/s41598-023-49817-4 (opens in new tab) Full text (opens in new tab) Psilocybin Escitalopram Clinical psychology Sexual dysfunction +2

Interactions between classic psychedelics and serotonergic antidepressants: Effects on the acute psychedelic subjective experience, well-being and depressive symptoms from a prospective survey study.

Journal of Psychopharmacology January 27, 2024 Jessica Barbut Siva, Tommaso Barba, Hannes Kettner et al. 29 citations

Background: There is growing evidence for the therapeutic effects of psychedelics. However, it is still uncertain how these drugs interact with serotonergic antidepressants (serotonin reuptake inhibitors (SRIs)). Objective: This study explores the interaction between psychedelics and SRIs in terms of therapeutic effects. The objective is to compare acute psychedelic effects and subsequent...

DOI: 10.1177/02698811231224217 (opens in new tab) Full text (opens in new tab) Psychedelics Antidepressants Mental health Drug interactions +1

Preliminary evidence for the importance of therapeutic alliance in MDMA-assisted psychotherapy for posttraumatic stress disorder.

European Journal of Psychotraumatology 2024 Richard J. Zeifman, Hannes Kettner, Stephen Ross et al. 34 citations

Background: MDMA-assisted psychotherapy (MDMA-AP) is a combined psychotherapeutic and pharmacologic intervention that shows promise in the treatment of posttraumatic stress disorder (PTSD). Although therapeutic alliance has been established as a key predictor across psychotherapies and is emphasised within MDMA-AP treatment manuals, research has not yet examined the relationship between...

DOI: 10.1080/20008066.2023.2297536 (opens in new tab) Full text (opens in new tab) MDMA-Assisted Psychotherapy Posttraumatic stress disorder Alianza terapéutica Mecanismos de cambio +2

Long-term benefits to psychological health and well-being after ceremonial use of Ayahuasca in Middle Eastern and North African immigrants and refugees.

Frontiers in Psychiatry 2024 Matthew X. Lowe, Hannes Kettner, Del R. P. Jolly et al. 9 citations

Refugees and immigrants can experience complex stressors from the process of immigration that can have lasting and severe long-term mental health consequences. Experiences after ayahuasca ingestion are shown to produce positive effects on psychological wellbeing and mental health, including anecdotal reports of improved symptoms of trauma and related disorders. However, data on the longitudinal...

The ego in psychedelic drug action – ego defenses, ego boundaries, and the therapeutic role of regression

Frontiers in Neuroscience October 6, 2023 Tobias Buchborn, Hannes Kettner, Laura Kärtner et al. 21 citations

The ego is one of the most central psychological constructs in psychedelic research and a key factor in psychotherapy, including psychedelic-assisted forms of psychotherapy. Despite its centrality, the ego-construct remains ambiguous in the psychedelic literature. Therefore, we here review the theoretical background of the ego-construct with focus on its psychodynamic conceptualization. We...

DOI: 10.3389/fnins.2023.1232459 (opens in new tab) Ego regression Ego defenses Ego boundary Psycholytic therapy +8

Co-use of MDMA with psilocybin/LSD may buffer against challenging experiences and enhance positive experiences

Scientific Reports August 22, 2023 Hannes Kettner, Stephen Ross, Richard J. Zeifman et al. 31 citations

Abstract Psilocybin and lysergic acid diethylamide (LSD) experiences can range from very positive to highly challenging (e.g., fear, grief, and paranoia). These challenging experiences contribute to hesitancy toward psychedelic-assisted psychotherapy among health care providers and patients. Co-use of 3,4-Methylenedioxy methamphetamine (MDMA) with psilocybin/LSD anecdotally reduces challenging...

Human brain effects of DMT assessed via EEG-fMRI.

Proceedings of the National Academy of Sciences March 28, 2023 Christopher Timmermann, Leor Roseman, Sharad Haridas et al. 217 citations

Psychedelics have attracted medical interest, but their effects on human brain function are incompletely understood. In a comprehensive, within-subjects, placebo-controlled design, we acquired multimodal neuroimaging [i.e., EEG-fMRI (electroencephalography-functional MRI)] data to assess the effects of intravenous (IV) N,N-Dimethyltryptamine (DMT) on brain function in 20 healthy volunteers....

Among psychedelic-experienced users, only past use of psilocybin reliably predicts nature relatedness

Journal of Psychopharmacology 2023 Matthias Forstmann, Christina Sagioglou, Alexander Irvine et al. 18 citations

Background: Past research reports a positive relationship between experience with classic serotonergic psychedelics and nature relatedness (NR). However, these studies typically do not distinguish between different psychedelic compounds, which have a unique psychopharmacology and may be used in specific contexts and with different intentions. Likewise, it is not clear whether these findings can...

Canalization and plasticity in psychopathology

Neuropharmacology December 27, 2022 Robin Carhart-Harris, Shamil Chandaria, David Erritzøe et al. 106 citations

This theoretical article revives a classical bridging construct, canalization, to describe a new model of a general factor of psychopathology. To achieve this, we have distinguished between two types of plasticity, an early one that we call 'TEMP' for 'Temperature or Entropy Mediated Plasticity', and another, we call 'canalization', which is close to Hebbian plasticity. These two forms of...

DOI: 10.1016/j.neuropharm.2022.109398 (opens in new tab) Psychopathology Plasticity Variance accounting Hebbian theory +1

Predictors Of Hallucinogen Persisting Perception Disorder Symptoms, Delusional Ideation And Magical Thinking Following Naturalistic Psychedelic Use

November 15, 2022 Katie Zhou, David de Wied, Robin Carhart-Harris et al. 8 citations preprint

OBJECTIVE: Psychedelics have over recent years been subject to a fast-paced growth in scientific research, clinical applications, commercial investment, and substance use trends by the general public. Yet, concerningly little is known about the frequency of adverse side effects of psychedelic use, despite a breadth of anecdotal reports and largely untested assumptions that inform the screening...

DOI: 10.31234/osf.io/txzha (opens in new tab) Full text (opens in new tab) Ideation Naturalistic observation Perception Clinical psychology +4

Effects of psilocybin versus escitalopram on rumination and thought suppression in depression

BJPsych Open September 1, 2022 Tommaso Barba, Sarah Buehler, Hannes Kettner et al. 57 citations

Background Major depressive disorder is often associated with maladaptive coping strategies, including rumination and thought suppression. Aims To assess the comparative effect of the selective serotonin reuptake inhibitor escitalopram, and the serotonergic psychedelic psilocybin (COMP360), on rumination and thought suppression in major depressive disorder. Method Based on data derived from a...

The Watts Connectedness Scale: a new scale for measuring a sense of connectedness to self, others, and world

Psychopharmacology August 8, 2022 Rosalind Watts, Hannes Kettner, Dana Geerts et al. 159 citations

Abstract Rationale A general feeling of disconnection has been associated with mental and emotional suffering. Improvements to a sense of connectedness to self, others and the wider world have been reported by participants in clinical trials of psychedelic therapy. Such accounts have led us to a definition of the psychological construct of ‘connectedness’ as ‘a state of feeling connected to...

Antidepressant effects of a psychedelic experience in a large prospective naturalistic sample.

Journal of Psychopharmacology August 1, 2022 Victoria Amalie Nygart, Lis Marie Pommerencke, Eline Haijen et al. 73 citations

Background: Over the last two decades, a number of studies have highlighted the potential of psychedelic therapy. However, questions remain to what extend these results translate to naturalistic samples, and how contextual factors and the acute psychedelic experience relate to improvements in affective symptoms following psychedelic experiences outside labs/clinics. The present study sought to...

DOI: 10.1177/02698811221101061 (opens in new tab) Full text (opens in new tab) Psychedelic therapy Depression treatment Mental well-being Clinical research +10

From Relaxed Beliefs Under Psychedelics (REBUS) to Revised Beliefs After Psychedelics (REBAS): Preliminary Development of the RElaxed Beliefs Questionnaire (REB-Q)

July 7, 2022 Richard J. Zeifman, Meg J. Spriggs, Hannes Kettner et al. 13 citations preprint

Background: The Relaxed Beliefs Under pSychedelics (REBUS) model proposes that serotonergic psychedelics decrease the precision weighting of neurobiologically-encoded beliefs, and offers a unified account of the acute and therapeutic action of psychedelics. Although REBUS has received some neuroscientific support, little research has examined its psychological validity. We conducted a...

Therapeutic Alliance and Rapport Modulate Responses to Psilocybin Assisted Therapy for Depression

Frontiers in Pharmacology March 31, 2022 Roberta Murphy, Roberta Murphy, Hannes Kettner et al. 229 citations

Background: Across psychotherapeutic frameworks, the strength of the therapeutic alliance has been found to correlate with treatment outcomes; however, its role has never been formally assessed in a trial of psychedelic-assisted therapy. We aimed to investigate the relationships between therapeutic alliance and rapport, the quality of the acute psychedelic experience and treatment outcomes....

DOI: 10.3389/fphar.2021.788155 (opens in new tab) Mystical experience Therapeutic relationship Emotional breakthrough Psilocybin therapy: psilocybin +4

Validation of the Psychological Insight Scale: A new scale to assess psychological insight following a psychedelic experience.

Journal of Psychopharmacology January 5, 2022 Joseph Peill, Katie Trinci, Hannes Kettner et al. 135 citations

Introduction: As their name suggests, 'psychedelic' (mind-revealing) compounds are thought to catalyse processes of psychological insight; however, few satisfactory scales exist to sample this. This study sought to develop a new scale to measure psychological insight after a psychedelic experience: the Psychological Insight Scale (PIS). Methods: The PIS is a six- to seven-item questionnaire...

DOI: 10.1177/02698811211066709 (opens in new tab) Full text (opens in new tab) Psychedelic research Psychological insight Psychometric scale Therapeutic potential

Psychedelics alter metaphysical beliefs.

Scientific Reports November 23, 2021 Christopher Timmermann, Hannes Kettner, Chris Letheby et al. 208 citations

Can the use of psychedelic drugs induce lasting changes in metaphysical beliefs? While it is popularly believed that they can, this question has never been formally tested. Here we exploited a large sample derived from prospective online surveying to determine whether and how beliefs concerning the nature of reality, consciousness, and free-will, change after psychedelic use. Results revealed...

Psychedelic experience dose-dependently modulated by cannabis: results of a prospective online survey.

Psychopharmacology November 4, 2021 Joanna Kuć, Hannes Kettner, Fernando E. Rosas et al. 37 citations

RATIONALE: Classic psychedelics are currently being studied as novel treatments for a range of psychiatric disorders. However, research on how psychedelics interact with other psychoactive substances remains scarce. OBJECTIVES: The current study aimed to explore the subjective effects of psychedelics when used alongside cannabis. METHODS: Participants (n = 321) completed a set of online surveys...

DOI: 10.1007/s00213-021-05999-1 (opens in new tab) Full text (opens in new tab) Psychedelics Cannabis/marijuana/weed Drug interactions Altered states +1

Sustained, Multifaceted Improvements in Mental Well-Being Following Psychedelic Experiences in a Prospective Opportunity Sample

Frontiers in Psychiatry June 29, 2021 Keri Mans, Hannes Kettner, David Erritzøe et al. 65 citations

In the last 15 years, psychedelic substances, such as LSD and psilocybin, have regained legitimacy in clinical research. In the general population as well as across various psychiatric populations, mental well-being has been found to significantly improve after a psychedelic experience. Mental well-being has large socioeconomic relevance, but it is a complex, multifaceted construct. In this...

DOI: 10.3389/fpsyt.2021.647909 (opens in new tab) Psilocybin Mental health Well-being Clinical psychology +3

Psychedelics and health behaviour change

Journal of Psychopharmacology May 29, 2021 Pedro J. Teixeira, Matthew W. Johnson, Christopher Timmermann et al. 87 citations

Healthful behaviours such as maintaining a balanced diet, being physically active and refraining from smoking have major impacts on the risk of developing cancer, diabetes, cardiovascular diseases and other serious conditions. The burden of the so-called ‘lifestyle diseases’—in personal suffering, premature mortality and public health costs—is considerable. Consequently, interventions designed...

Turn on, Tune in, and Drop out: Predictors of Attrition in a Prospective Observational Cohort Study on Psychedelic Use

Journal of Medical Internet Research May 4, 2021 Sebastian Hübner, Eline Haijen, Mendel Kaelen et al. 23 citations

Background The resurgence of research and public interest in the positive psychological effects of psychedelics, together with advancements in digital data collection techniques, have brought forth a new type of research design, which involves prospectively gathering large-scale naturalistic data from psychedelic users; that is, before and after the use of a psychedelic compound. A...

DOI: 10.2196/25973 (opens in new tab) Attrition Health psychology Logistic regression Personality +4

Positive effects of psychedelics on depression and wellbeing scores in individuals reporting an eating disorder.

Eating and Weight Disorders - Studies on Anorexia Bulimia and Obesity May 1, 2021 M J Spriggs, Hannes Kettner, R L Carhart-Harris

Psychedelic therapy is showing promise for a broad range of mental health conditions, indicative of a transdiagnostic action. While the efficacy of symptom-focused treatments for eating disorders (EDs) is limited, improved mental health and psychological wellbeing are thought to contribute to greater treatment outcomes. This study provides the first quantitative exploration of the psychological...

DOI: 10.1007/s40519-020-01000-8 (opens in new tab) Full text (opens in new tab) Anorexia Binge eating disorder Bulimia Longitudinal +2