Role of the Serotonin 5-HT2A Receptor in Mescaline-induced Altered States of Consciousness
试验速览
- 阶段
- 1 期
- 状态
- 已完成
- 发起方
- 入组人数
- 16
- 试验地点
- 1
- 主要终点
- Altered States of Consciousness
研究概览
简要总结
Mescaline (the active substance in Peyote and San Pedro cacti) is a classic and long known serotonergic psychedelic substance (hallucinogen) that is widely used for recreational, spiritual, and/or ethno medical purposes. Despite its long history, modern data on the acute effects of mescaline on human is lacking. Mescaline produces prototypical psychedelic effects, similar as lysergic acid diethylamide (LSD) and psilocybin. The serotonin 2A (5-HT2A) receptor is thought to primarily mediate acute alterations of consciousness induced by LSD and psilocybin. However, the contributory role of the 5-HT2A receptor in mescaline-induced alterations of consciousness is unclear. Using 5-HT2A receptor antagonist ketanserin, the psychedelic experience induced by LSD and psilocybin can be attenuated and shortened. The present study therefore explores the role the 5-HT2A receptor in mescaline-induced altered states of consciousness using escalating doses of mescaline and the 5-HT2A receptor blocker ketanserin administered before a high dose of mescaline.
Objective: The present MDR-study will characterize the subjective effects of different doses of mescaline using modern psychometric instruments and examine the contribution of the 5-HT2A receptor in the mescaline-induced alterations of consciousness.
Design: Double-blind, placebo-controlled, 6-period cross-over design with six treatment conditions. 1) Placebo (Pla + Pla), 2) 100 mg mescaline (Pla + 100mg mescaline), 3) 200 mg mescaline (Pla + 200mg mescaline), 4) 400 mg mescaline (Pla + 400mg mescaline), 5) 800 mg mescaline (Pla + 800mg mescaline), and 6) 40mg ketanserin and 800mg mescaline (Ket + 800mg mescaline).
Participants: 16 healthy participants aged ≥ 25 and ≤ 65 years (8 female, 8 male)
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 25 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age between 25 and 65 years old
- •Sufficient understanding of the German language
- •Understanding of procedures and risks associated with the study
- •Willing to adhere to the protocol and signing of the consent form
- •Willing to refrain from the consumption of illicit psychoactive substances during the study
- •Abstaining from xanthine-based liquids from the evenings prior to the study sessions to the end of the study days
- •Willing not to drive a traffic vehicle or operate heavy machinery within 48 hours after substance administration
- •Willing to use double-barrier birth control throughout study participation
- •Body mass index between 18-29 kg/m2
排除标准
- •Chronic or acute medical condition
- •Current or previous major psychiatric disorder
- •Psychotic disorder or bipolar disorder in first-degree relatives
- •Hypertension (>140/90 mmHg) or hypotension (SBP10 cigarettes/day)
- •Hallucinogenic substance use (not including cannabis) more than 20 times or any time within the previous two months
- •Pregnancy or current breastfeeding
- •Participation in another clinical trial (currently or within the last 30 days)
- •Use of medication that may interfere with the effects of the study medication
- •Tobacco smoking (>10 cigarettes/day)
- •Consumption of alcoholic beverages (>20 drinks/week)
研究组 & 干预措施
Placebo + Placebo
干预措施: Placebo (Drug)
Mescaline-100 + Placebo
干预措施: Mescaline 100mg (Drug)
Mescaline-200 + Placebo
干预措施: Mescaline 200mg (Drug)
Mescaline-400 + Placebo
干预措施: Mescaline 400mg (Drug)
Mescaline-800 + Placebo
干预措施: Mescaline 800mg (Drug)
Mescaline-800 + Ketanserin
干预措施: Mescaline 800mg + Ketanserin 40mg (Drug)
结局指标
主要结局
Altered States of Consciousness
时间窗: 18 months
5 Dimensions of Altered States of Consciousness (5D-ASC) assesses mood, anxiety, derealization, depersonalization, changes in perception, auditory alterations, and reduced vigilance. The questionnaire is consisting of 94 items to be rated on a visual analog scale (horizontal line, 100 mm, marked with "not at all" on the left and "extremely" on the right), with higher values indicating stronger effects. Subjects will mark the scale with vertical lines.
次要结局
- Emotional effects(18 months)
- Subjective mood ratings(18 months)
- States of Consciousness(18 months)
- Extent of subjective response over time(18 months)
- Subjective experiences of spiritual phenomenons(18 months)
- Mystical-type experiences(18 months)
- Effects on oxytocin(18 months)
- Blood pressure(18 months)
- Heart rate(18 months)
- Body temperature(18 months)
- Pupil size(18 months)
- Mescaline concentrations in the blood(18 months)
- Mescaline concentrations in the urine(18 months)
- Effects on brain-derived neurotrophic factor (BDNF)(18 months)
- Effects on inflammatory cytokines(18 months)
- Effect moderation through personality traits I(18 months)
- Effect moderation through personality traits II(18 months)
- Effect moderation through personality traits III(18 months)
- Effect moderation through personality traits IV(18 months)
- Effect moderation through personality traits V(18 months)
- Psychological insight(18 months)
- Effects on life satisfaction, well-being and appreciation I(18 months)
- Effects on life satisfaction, well-being and appreciation II(18 months)
- Effects on life satisfaction, well-being and appreciation III(18 months)
- Effects on life satisfaction, well-being and appreciation IV(18 months)
- Incidence of Adverse Events before and during each study session(18 months)
- Incidence of Adverse Events during each study session(18 months)
- Electrical activity of the heart(18 months)