Publications by authors named "Matthias Liechti"

N,N-dimethyltryptamine (DMT) is a serotonergic psychedelic that is known for its short-lasting effects when administered intravenously. Several studies have investigated the administration of intravenous boluses or combinations of a bolus and a subsequent continuous infusion. However, data on dose-dependent acute effects and pharmacokinetics of continuous DMT infusions are lacking.

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The antidepressant-like activity of two psychoplastogens, ibogainalog (IBG) and ibogaminalog (DM506), was studied in naïve mice using the forced swim test (FST) and tail suspension test (TST). The behavioral results showed that a single administration of 25 mg/kg DM506 or 10 mg/kg IBG induced antidepressant-like activity in naïve mice in a volinanserin-sensitive manner that persisted for 72 h. Similar results were observed using the chronic immobilization stress (CIS) test, in which depression symptoms were reduced for 48 h.

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Aims: Psychedelics, including mescaline, may serve as novel treatments for depression and anxiety. However, data is scarce on the safety of mescaline.

Methods: The present pooled analysis included two double-blind, randomized, placebo-controlled studies with a total of 48 participants and 96 mescaline administrations.

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  • MDMA (ecstasy) is being studied as a treatment for PTSD but has the risk of causing low sodium levels (hyponatremia) after just one dose due to factors like vasopressin release and excessive drinking.
  • This study aimed to analyze how often and severely hyponatremia occurs after a single MDMA dose, looking at underlying hormonal mechanisms and whether limiting fluid intake could reduce this risk.
  • Out of 96 participants, about 31% experienced hyponatremia, but none in the group with fluid restrictions, suggesting that managing fluid intake could lessen the chance of developing this complication.
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  • - Classic psychedelics like mescaline have renewed interest in therapy, but there's limited modern data on its effects and mechanisms of action in humans due to a lack of comprehensive studies.
  • - In a study with 16 healthy participants, mescaline was administered in varying doses (100-800 mg) to assess subjective and autonomic effects, showing that higher doses produced stronger effects, increased heart rate, and elevated blood pressure without notable differences between doses above 100 mg.
  • - The combination of mescaline and the 5-HT receptor antagonist ketanserin decreased and shortened the effects of the highest dose, suggesting the acute effects of mescaline are mainly mediated by these serotonin receptors, while nausea was a common
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Background: Psychedelic-assisted therapy (PAT) is permitted in Switzerland under its limited medical use program. Data from patients in this program represent a unique opportunity to analyze the real-world practice of PAT.

Aims: This study compared the subjective effects of lysergic acid diethylamide (LSD) and psilocybin between patients undergoing PAT and healthy volunteers.

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Psychedelics have recently attracted significant attention for their potential to mitigate symptoms associated with various psychiatric disorders. However, the precise neurobiological mechanisms responsible for these effects remain incompletely understood. A valuable approach to gaining insights into the specific mechanisms of action involves comparing psychedelics with substances that have partially overlapping neurophysiological effects, i.

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The pharmacodynamic effects of lysergic acid diethylamide (LSD) are diverse and different in different individuals. Effects of other psychoactive substances have been shown to be critically influenced by non-pharmacological factors such as personality traits and mood states. The aim of this study was to determine pharmacological and psychological predictors of the LSD effects in healthy human subjects.

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  • MDMA, known for boosting mood and empathy, was compared with its enantiomers S-MDMA and R-MDMA in a controlled study to explore their effects on participants' experiences of stimulation and psychedelia.
  • S-MDMA (125 mg) produced stronger subjective effects and increased blood pressure compared to both R-MDMA doses and regular MDMA, while R-MDMA did not show notable psychedelic effects as expected.
  • Pharmacokinetic analysis revealed that S-MDMA has a shorter elimination half-life (4.1 hours) and results in higher plasma levels of prolactin, cortisol, and oxytocin compared to R-MDMA, which has a longer half-life (12-14 hours) and weaker stimulant
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  • The serotonin 2A (5-HT2A) receptor plays a key role in the effects of classical psychedelics and is a target for new drug development.
  • A PET study was conducted to examine how ketanserin, a 5-HT2A receptor antagonist, affects receptor occupancy in healthy participants after different doses.
  • The findings indicate that ketanserin increases 5-HT2A receptor occupancy in a dose-dependent manner, providing insights into its potential therapeutic applications and usefulness in studying brain function.
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Psychedelics are a group of substances within the heterogeneous class of hallucinogenic drugs. Via binding to the serotonin (5-HT) 2A receptor, psychedelics exert profound alterations in various mental domains, including sensation, cognition, emotions, and self-perception. Psychedelics comprise phenethylamines (e.

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Background: Anxiety disorders are a major public health burden with limited treatment options.

Aims: We investigated the long-term safety and efficacy of lysergic acid diethylamide (LSD)-assisted therapy in patients with anxiety with or without life-threatening illness.

Method: This study was an -planned long-term follow-up of an investigator-initiated, two-centre trial that used a double-blind, placebo-controlled, two-period, random-order, crossover design with two sessions with either oral LSD (200 μg) or placebo per period.

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Science on methylenedioxymethamphetamine (MDMA) and MDMA-like substances is faced with the unique situation that this class of psychoactive agents is referred to with two basic names for its effects on the mind: empathogens and entactogens. Empathogen usually refers to the prosocial, empathetic, and openness properties of MDMA, while entactogen usually refers to the introspective and self-awareness properties of this substance. We review the origin and usage of the two terms, and also review recent findings that support that MDMA is an empathogen and an entactogen.

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  • Microdosing psychedelics, particularly LSD, is gaining popularity for potential mental health benefits, but studies show mixed results, possibly due to individual differences in reactions.
  • A study with 53 healthy participants tested low doses of LSD (15 mcg) and a placebo, measuring arousal, attention, and memory through various neurophysiological assessments over two weeks.
  • Results indicated that LSD increased arousal and attention mainly in those with lower baseline states while inhibiting memory performance in high achievers; effects were still noticeable a week after treatment, suggesting lasting changes.
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  • This study evaluates the clinical features and outcomes of acute cannabis toxicity versus acute synthetic cannabinoid receptor agonist toxicity in European emergency departments from 2013-2020.
  • Using data from the European Drug Emergencies Network Plus, researchers analyzed 2,657 cases of cannabis exposure and 503 cases of synthetic cannabinoid exposure to compare their effects.
  • The findings indicate that synthetic cannabinoid exposures are linked to more severe neuropsychiatric symptoms, while cannabis exposures are associated with cardiovascular issues.
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The aim of this study was to determine the anti-hypersensitivity activity of novel non-hallucinogenic compounds derived from iboga alkaloids (i.e., ibogalogs), including tabernanthalog (TBG), ibogainalog (IBG), and ibogaminalog (DM506), using mouse models of neuropathic (Chronic Constriction Injury; CCI) and visceral pain (dextrane sulfate sodium; DSS).

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  • Psilocybin is quickly converted to psilocin, which produces psychedelic effects by targeting the 5-HT receptor, and its metabolism involves converting psilocin to other compounds like 4-HIAA and 4-HTP.
  • The study analyzed metabolic processes using human liver microsomes and various enzymes, revealing that male C57BL/6J mice and human samples showed different metabolic rates and pathways for psilocin.
  • Key enzymes such as MAO-A, CYP2D6, and CYP3A4 play roles in psilocin metabolism, with the identification of new metabolites like norpsilocin and oxidized psilocin, which could inform future research on drug interactions and ps
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3,4-Methylenedioxymethamphetamine (MDMA) is an entactogen with therapeutic potential. The two enantiomers of MDMA differ regarding their pharmacokinetics and pharmacodynamics but the chiral pharmacology of MDMA needs further study in clinical trials. Here, an achiral and an enantioselective high performance liquid chromatography-tandem mass spectrometry method for the quantification of MDMA and its psychoactive phase I metabolite 3,4-methylenedioxyamphetamine (MDA) in human plasma were developed and validated.

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Diamorphine, commonly known as heroin, is a semi-synthetic opioid analgesic. In the context of heroin-assisted treatment for opioid-dependent patients, diamorphine is mostly administered intravenously. However, recent attention has shifted towards intranasal administration as a better-tolerated alternative to the intravenous route.

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  • Distinguishing between arginine vasopressin deficiency (AVP-D) and primary polydipsia (PP) is difficult, and there's a lack of comparative data on their psychopathological features.
  • A study involving 82 participants used standardized questionnaires to assess anxiety, alexithymia, depression, and overall mental health, finding both AVP-D and PP patients exhibited significantly higher levels of these issues compared to healthy controls.
  • The findings indicate that AVP-D and PP patients have similar psychological challenges, suggesting that careful interpretation of these characteristics is essential for accurate diagnosis.
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Psychedelic compounds, including psilocybin, LSD (lysergic acid diethylamide), DMT (N,N -dimethyltryptamine), and 5-MeO-DMT (5-methoxy-N,N-dimethyltryptamine), all of which are serotonin 2A receptor agonists, are being investigated as potential treatments. This review aims to summarize the current clinical research on these 4 compounds and mescaline to guide future research. Their mechanism(s) of action, pharmacokinetics, pharmacodynamics, efficacy, and safety were reviewed.

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  • The study investigated the effects of DM506, a non-hallucinogenic compound from ibogamine, on anxiety and sedation in mice using various behavioral tests.
  • Findings revealed that a dose of 15 mg/kg DM506 provided both acute and lasting anxiolytic effects, while higher doses (40 mg/kg) produced sedative effects that could be blocked by a specific 5-HT receptor antagonist.
  • Electroencephalography showed that DM506 altered brain activity from alertness to deep sleep, demonstrating its potential as a safe anxiolytic and sedative without the hallucinogenic side effects typical of other compounds.
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The acute psychoactive, autonomic, and endocrine effects of the new psychoactive substance (NPS) 5,6-methylenedioxy-2-aminoindane (MDAI; 3.0 mg/kg, range 180-228 mg) were investigated in six healthy volunteers (four males, two females) in a non-blinded fashion without placebo. Subjective, cardiovascular, and endocrine responses were compared with two different doses of 3,4-methylenedioxymethamphetamine (MDMA) (75 mg and 125 mg) described in previously published placebo-controlled studies, which used identical outcome measures including Visual Analogue Scales (VAS), the Adjective Mood Rating Scale (AMRS), and the 5 Dimensions of Altered States of Consciousness (5D-ASC) scale.

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  • * Data from 11 centers across seven European countries revealed a wide variation in self-discharge rates, ranging from 1.7% to 17.1%, with synthetic cannabinoids and heroin use linked to higher rates of self-discharge.
  • * Strategies to enhance agitation management and the careful use of naloxone may help reduce self-discharge rates in ED settings.
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