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Johannes G. Ramaekers

Maastricht University

114 papers in the library · 4,340 citations · publishing 2003-2026

Papers

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Psychedelic-Assisted Psychotherapy—A Systematic Review of Associated Psychological Interventions

Frontiers in Psychology June 10, 2022 Mauro Cavarra, Alessandra Falzone, Johannes G. Ramaekers et al. 156 citations

Modern clinical research on psychedelics is generating interesting outcomes in a wide array of clinical conditions when psychedelic-assisted psychotherapy is delivered to appropriately screened participants and in controlled settings. Still, a number of patients relapse or are less responsive to such treatments. Individual and contextual factors (i.e., set and setting) seem to play a role in...

DOI: 10.3389/fpsyg.2022.887255 (opens in new tab) Psychotherapist Psycinfo Context archaeology Psychological intervention +5

A Comparison of Acute Neurocognitive and Psychotomimetic Effects of a Synthetic Cannabinoid and Natural Cannabis at Psychotropic Dose Equivalence

Frontiers in Psychiatry May 19, 2022 Eef L. Theunissen, Kim P. C. Kuypers, Natasha L. Mason et al. 7 citations

Due to differences in potency, efficacy, and affinity for CB1 receptors, similarities and differences in psychoactive effect profiles of natural cannabis and synthetic cannabinoids (SCs) cannot reliably be derived from equipotent dose comparisons. Instead, the current study proposes to compare the intrinsic psychoactive effects of natural cannabis (THC) and an SC, JWH-018, at psychotropic dose...

DOI: 10.3389/fpsyt.2022.891811 (opens in new tab) Cannabis Psychotomimetic Neurocognitive Pharmacology +9

Cannabis Use and Neuroadaptation: A Call for Δ9-Tetrahydrocannabinol Challenge Studies

Frontiers in Psychiatry April 14, 2022 Johannes G. Ramaekers, Eef L. Theunissen, Peter van Ruitenbeek et al. 6 citations

Currently, the assessment of the neurobehavioral consequences of repeated cannabis use is restricted to studies in which brain function of chronic cannabis users is compared to that of non-cannabis using controls. The assumption of such studies is that changes in brain function of chronic users are caused by repeated and prolonged exposure to acute cannabis intoxication. However, differences in...

DOI: 10.3389/fpsyt.2022.870750 (opens in new tab) Cannabidiol Effects of cannabis Neurocognitive Delta-9-tetrahydrocannabinol +3

Metabolomics and integrated network analysis reveal roles of endocannabinoids and large neutral amino acid balance in the ayahuasca experience

Biomedicine & Pharmacotherapy March 24, 2022 Francisco Madrid-Gambin, Alex Gomez-Gomez, Arnau Busquets-García et al. 14 citations

There has been a renewed interest in the potential use of psychedelics for the treatment of psychiatric conditions. Nevertheless, little is known about the mechanism of action and molecular pathways influenced by ayahuasca use in humans. Therefore, for the first time, our study aims to investigate the human metabolomics signature after consumption of a psychedelic, ayahuasca, and its connection...

Persisting decreases in state and trait anxiety post-psilocybin: A naturalistic, observational study among retreat attendees

medRxiv March 2, 2022 Maggie Kiraga, Kim P. C. Kuypers, Malin V. Uthaug et al. preprint

Abstract Anxiety disorders are the most common type of psychiatric disorders among Western countries. Evidence-based treatment modalities including pharmacological and cognitive-behavioral therapy result in relatively low response rates (average range: 51 - 58%). Historical and recent research suggests psychedelic drugs may be efficacious in alleviating anxiety-related symptoms among healthy...

The epidemiology of mescaline use: Pattern of use, motivations for consumption, and perceived consequences, benefits, and acute and enduring subjective effects.

Journal of Psychopharmacology March 1, 2022 Malin Vedøy Uthaug, Alan K. Davis, Trevor Forrest Haas et al. 64 citations

Mescaline is a naturally occurring psychoactive phenethylamine found in several cacti and historically used ceremonially by Indigenous and Latin American populations. Broader recognition of its possible therapeutic value in Western science began in the 1950s; however, knowledge of the safety profile of mescaline and the extent of its use remains limited. The primary aim of this study is to...

Functional brain connectomes reflect acute and chronic cannabis use

Scientific Reports February 14, 2022 Johannes G. Ramaekers, Natasha L. Mason, Stefan W. Toennes et al. 26 citations

Resting state fMRI has been employed to identify alterations in functional connectivity within or between brain regions following acute and chronic exposure to Δ9-tetrahydrocannabinol (THC), the psychoactive component in cannabis. Most studies focused a priori on a limited number of local brain areas or circuits, without considering the impact of cannabis on whole-brain network organization....

The clinical pharmacology and potential therapeutic applications of 5‐methoxy‐N,N‐dimethyltryptamine (5‐MeO‐DMT)

Journal of Neurochemistry February 12, 2022 Johannes T. Reckweg, Malin V. Uthaug, Attila Szabo et al. 108 citations

Abstract 5‐methoxy‐N,N‐dimethyltryptamine (5‐MeO‐DMT) is a naturally occurring tryptamine that primarily acts as an agonist at the 5‐HT1A and 5‐HT2A receptors, whereby affinity for the 5‐HT1A subtype is highest. Subjective effects following 5‐MeO‐DMT administration include distortions in auditory and time perception, amplification of emotional states, and feelings of ego dissolution that...

DOI: 10.1111/jnc.15587 (opens in new tab) Anxiety Agonist Depression economics Pharmacology +1

Remembering Molly: Immediate and delayed false memory formation after acute MDMA exposure

European Neuropsychopharmacology February 3, 2022 Lilian Kloft, Henry Otgaar, Arjan Blokland et al. 17 citations

The entactogen 3,4-Methylenedioxymethamphetamine (MDMA) is increasingly being recognized for its therapeutic potential but is also widespread in nightlife settings where it may co-occur with crime. Since previous research detected impaired verbal memory during acute MDMA intoxication, understanding the drug's ramifications in an applied legal context becomes crucial. We conducted a...

LSD and creativity: Increased novelty and symbolic thinking, decreased utility and convergent thinking

Journal of Psychopharmacology February 1, 2022 Isabel Wießner, Marcelo Falchi-Carvalho, Lucas Oliveira Maia et al. 43 citations

Background: Controversy surrounds psychedelics and their potential to boost creativity. To date, psychedelic studies lack a uniform conceptualization of creativity and methodologically rigorous designs. Aims: This study aimed at addressing previous issues by examining the effects of lysergic acid diethylamide (LSD) on creativity using multimodal tasks and multidimensional approaches. Methods:...

DOI: 10.1177/02698811211069113 (opens in new tab) Creativity Divergent thinking Originality Cognitive psychology +9

Sex differences in acute cannabis effects revisited: Results from two randomized, controlled trials

Addiction Biology December 22, 2021 Thomas R. Arkell, Richard C. Kevin, Frederick Vinckenbosch et al. 45 citations

Some evidence suggests that males and females may differ in their responses to acute cannabis effects, including subjective drug effects and behavioural effects, and cannabinoid pharmacokinetics. This is significant given current changes to cannabis-related policies and, in consequence, increased cannabis accessibility. The present study combines data from two randomized controlled trials to...

DOI: 10.1111/adb.13125 (opens in new tab) Cannabidiol Randomized controlled trial Effects of cannabis Cannabis dependence +1

An experience with Holotropic Breathwork is associated with improvement in non-judgement and satisfaction with life while reducing symptoms of stress in a Czech-speaking population

Journal of Psychedelic Studies December 15, 2021 Malin V. Uthaug, Natasha L. Mason, Martha N. Havenith et al. 15 citations

Abstract Background Holotropic breathwork (Grof ® Breathwork), was developed by Stanislav Grof and Christina Grof as a ‘non-drug’ alternative technique to evoke altered states of consciousness (ASC). Interestingly, although HBW has been anecdotally reported to evoke experiences and mental health effects corresponding to those of psychedelic substances, the scientific literature on the matter is...

Persisting Effects of Ayahuasca on Empathy, Creative Thinking, Decentering, Personality, and Well-Being

Frontiers in Pharmacology October 1, 2021 Maggie Kiraga, Natasha L. Mason, Malin V. Uthaug et al. 83 citations

Background: Naturalistic and placebo-controlled studies have suggested that ayahuasca, a traditional Amazonian beverage, could be helpful in the treatment of psychopathologies like depression and anxiety disorders by changing otherwise disturbed cognitive and emotional processes. To better understand its full therapeutic potential, one way is to study the effects on processes like flexible...

Sub-acute and long-term effects of ayahuasca on mental health and well-being in healthy ceremony attendants: A replication study

Journal of Psychedelic Studies August 26, 2021 Kim van Oorsouw, Malin V. Uthaug, Natasha L. Mason et al. 16 citations

Abstract Background and aims There is a growing body of evidence suggesting that the psychedelic plant tea, ayahuasca, holds therapeutic potential. Uthaug et al. (2018) demonstrated that a single dose of ayahuasca improved mental health sub-acutely and 4-weeks post-ceremony in healthy participants. The present study aimed to replicate and extend these findings. A first objective was to assess...

The why behind the high: determinants of neurocognition during acute cannabis exposure.

Nature Reviews Neuroscience July 1, 2021 Johannes G. Ramaekers, Natasha L. Mason, Lilian Kloft et al.

Acute cannabis intoxication may induce neurocognitive impairment and is a possible cause of human error, injury and psychological distress. One of the major concerns raised about increasing cannabis legalization and the therapeutic use of cannabis is that it will increase cannabis-related harm. However, the impairing effect of cannabis during intoxication varies among individuals and may not...

The Setting Questionnaire for the Ayahuasca Experience: Questionnaire Development and Internal Structure

Frontiers in Psychology June 23, 2021 Alexandre Augusto de Deus Pontual, Luís Fernando Tófoli, Carlos Fernando Collares et al. 14 citations

The growing interest in research on psychedelic consumption in naturalistic contexts and their possible medical and therapeutic benefits requires assessment of the relationships between the substance and the individual who consumes it (set) and its context of use (setting). This study provides a novel measurement scale for the setting of Ayahuasca consumption, the Setting Questionnaire for the...

DOI: 10.3389/fpsyg.2021.679016 (opens in new tab) Ayahuasca Scale ratio Context archaeology Structural equation modeling +2

Naturalistic Use of Mescaline Is Associated with Self-Reported Psychiatric Improvements and Enduring Positive Life Changes.

ACS Pharmacology & Translational Science April 9, 2021 Gabrielle Agin-Liebes, Trevor F Haas, Rafael Lancelotta et al. 121 citations

Mescaline is a naturally occurring psychoactive alkaloid that has been used as a sacrament by Indigenous populations in spiritual ritual and healing ceremonies for millennia. Despite promising early preliminary research and favorable anecdotal reports, there is limited research investigating mescaline's psychotherapeutic potential. We administered an anonymous online questionnaire to adults (N...

Spontaneous and deliberate creative cognition during and after psilocybin exposure

Translational Psychiatry April 8, 2021 Natasha L. Mason, Kim P. C. Kuypers, Johannes T. Reckweg et al. 132 citations

Abstract Creativity is an essential cognitive ability linked to all areas of our everyday functioning. Thus, finding a way to enhance it is of broad interest. A large number of anecdotal reports suggest that the consumption of psychedelic drugs can enhance creative thinking; however, scientific evidence is lacking. Following a double-blind, placebo-controlled, parallel-group design, we...

A placebo-controlled study of the effects of ayahuasca, set and setting on mental health of participants in ayahuasca group retreats

Psychopharmacology March 10, 2021 Malin V. Uthaug, Natasha L. Mason, Stefan W. Toennes et al. 116 citations

Abstract Ayahuasca is a plant concoction containing N,N -dimethyltryptamine (DMT) and certain β-carboline alkaloids from South America. Previous research in naturalistic settings has suggested that ingestion of ayahuasca can improve mental health and well-being; however, these studies were not placebo controlled and did not control for the possibility of expectation bias. This naturalistic...

Psychotomimetic symptoms after a moderate dose of a synthetic cannabinoid (JWH-018): implications for psychosis

Psychopharmacology January 26, 2021 Eef L. Theunissen, Johannes T. Reckweg, Nadia R. P. W. Hutten et al. 20 citations

BACKGROUND: Synthetic cannabinoids (SCs) are the largest class of novel psychoactive substances (NPS) and are associated with an increased risk of overdosing and adverse events such as psychosis. JWH-018 is one of the earliest SCs and still widely available in large parts of the world. Controlled studies to assess the safety and behavioural profiles of SCs are extremely scarce. AIM: The current...

A Phase 1, Dose-Ranging Study to Assess Safety and Psychoactive Effects of a Vaporized 5-Methoxy-N, N-Dimethyltryptamine Formulation (GH001) in Healthy Volunteers.

Frontiers in Pharmacology 2021 Johannes T. Reckweg, Natasha L. Mason, Cees van Leeuwen et al. 58 citations

5-Methoxy-N,N-Dimethyltryptamine (5-MeO-DMT) is a tryptamine with ultra-rapid onset and short duration of psychedelic effects. Prospective studies for other tryptamines have suggested beneficial effects on mental health outcomes. In preparation for a study in patients with depression, the present study GH001-HV-101 aimed to assess the impact of four different dose levels of a novel vaporized...

Mood and cognition after administration of low LSD doses in healthy volunteers: A placebo controlled dose-effect finding study

European Neuropsychopharmacology October 17, 2020 Nadia R. P. W. Hutten, Natasha L. Mason, Patrick C. Dolder et al. 121 citations

There is a popular interest in microdosing with psychedelics such as LSD. This practice of using one-tenth of a full psychedelic dose according to a specific dosing schedule, anecdotally enhances mood and performance. Nonetheless, controlled research on the efficacy of microdosing is scarce. The main objective of the present dose-finding study was to determine the minimal dose of LSD needed to...

DOI: 10.1016/j.euroneuro.2020.10.002 (opens in new tab) Anxiety Mood Vigilance psychology Cognition +7

Pharmacokinetics and Pharmacodynamics of Lysergic Acid Diethylamide Microdoses in Healthy Participants

Clinical Pharmacology & Therapeutics September 25, 2020 Friederike Holze, Matthias E. Liechti, Nadia R. P. W. Hutten et al. 63 citations

“Microdoses” of lysergic acid diethylamide (LSD) are used recreationally to enhance mood and cognition. Increasing interest has also been seen in developing LSD into a medication. Therefore, we performed a pharmacokinetic‐pharmacodynamic study using very low doses of LSD. Single doses of LSD base (5, 10, and 20 µg) and placebo were administered in a double‐blind, randomized, placebo‐controlled...

DOI: 10.1002/cpt.2057 (opens in new tab) Lysergic acid diethylamide Pharmacodynamics Pharmacokinetics Pharmacology

Use characteristics and harm potential of ecstasy in The Netherlands

Drugs Education Prevention and Policy September 10, 2020 Jan Van Amsterdam, Johannes G. Ramaekers, Ton Nabben et al. 4 citations

Introduction Ecstasy (MDMA) is a popular recreational drug, but its illegal production and trade in the Netherlands have developed into a serious public order and ecological problem which endanger and question the harm reduction approach of the Dutch ecstasy policy.Methods The market characteristics, adverse health effects, risk profile, and link to criminal activity of ecstasy were...

Low Doses of LSD Acutely Increase BDNF Blood Plasma Levels in Healthy Volunteers

ACS Pharmacology & Translational Science August 31, 2020 Nadia R. P. W. Hutten, Natasha L. Mason, Patrick C. Dolder et al. 134 citations

Despite preclinical evidence for psychedelic-induced neuroplasticity, confirmation in humans is grossly lacking. Given the increased interest in using low doses of psychedelics for psychiatric indications and the importance of neuroplasticity in the therapeutic response, this placebo-controlled within-subject study investigated the effect of single low doses of LSD (5, 10, and 20 μg) on...