OPEN Foundation

Day: 7 November 2017

Double-blind comparison of the two hallucinogens psilocybin and dextromethorphan: similarities and differences in subjective experiences

November 7, 2017 / Mushrooms / Psilocybin, Other substances, Papers, Phenomenology, Psychology, Publications / By / , , ,

Abstract

Rationale

Although psilocybin and dextromethorphan (DXM) are hallucinogens, they have different receptor mechanisms of action and have not been directly compared.

Objective

This study compared subjective, behavioral, and physiological effects of psilocybin and dextromethorphan under conditions that minimized expectancy effects.

Methods

Single, acute oral doses of psilocybin (10, 20, 30 mg/70 kg), DXM (400 mg/70 kg), and placebo were administered under double-blind conditions to 20 healthy participants with histories of hallucinogen use. Instructions to participants and staff minimized expectancy effects. Various subjective, behavioral, and physiological effects were assessed after drug administration.

Results

High doses of both drugs produced similar increases in participant ratings of peak overall drug effect strength, with similar times to maximal effect and time-course. Psilocybin produced orderly dose-related increases on most participant-rated subjective measures previously shown sensitive to hallucinogens. DXM produced increases on most of these same measures. However, the high dose of psilocybin produced significantly greater and more diverse visual effects than DXM including greater movement and more frequent, brighter, distinctive, and complex (including textured and kaleidoscopic) images and visions. Compared to DXM, psilocybin also produced significantly greater mystical-type and psychologically insightful experiences and greater absorption in music. In contrast, DXM produced larger effects than psilocybin on measures of disembodiment, nausea/emesis, and light-headedness. Both drugs increased systolic blood pressure, heart rate, and pupil dilation and decreased psychomotor performance and balance.

Conclusions

Psilocybin and DXM produced similar profiles of subjective experiences, with psilocybin producing relatively greater visual, mystical-type, insightful, and musical experiences, and DXM producing greater disembodiment.

Carbonaro, T. M., Johnson, M. W., Hurwitz, E., & Griffiths, R. R. (2017). Double-blind comparison of the two hallucinogens psilocybin and dextromethorphan: similarities and differences in subjective experiences. Psychopharmacology, 1-14. 10.1007/s00213-017-4769-4
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Why MDMA therapy for alcohol use disorder? And why now?

November 7, 2017 / Addiction, MDMA, Papers, Psychiatry, Psychology, Psychotherapy, Publications / By /

Abstract

Alcohol use disorder represents a serious clinical, social and personal burden on its sufferers and a significant financial strain on society. Current treatments, both psychological and pharmacological are poor, with high rates of relapse after medical detoxification and dedicated treatment programs. The earliest historical roots of psychedelic drug-assisted psychotherapy in the 1950s were associated with Lysergic acid diethylamide (LSD)-assisted psychotherapy to treat what was then called, alcoholism. But results were varied and psychedelic therapy with LSD and other ‘classical’ psychedelics fell out of favour in the wake of socio-political pressures and cultural changes. A current revisiting of psychedelic clinical research is now targeting substance use disorders – and particularly alcohol use disorder – again. 3,4-Methylenedioxymethamphetamine (MDMA)-assisted psychotherapy has never been formally explored as a treatment for any form of substance use disorder. But in recent years MDMA has risen in prominence as an agent to treat posttraumatic stress disorder (PTSD). With its unique receptor profile and a relatively well-tolerated subjective experience of drug effects when used clinically, MDMA Therapy is ideally suited to allow a patient to explore and address painful memories without being overwhelmed by negative affect. Given that alcohol use disorder is so often associated with early traumatic experiences, the author is proposing in a current on-going UK-based study that patients with alcohol use disorder who have undergone a medical detoxification from alcohol might benefit from a course of MDMA-assisted psychotherapy.

Sessa, B. (2017). Why MDMA therapy for alcohol use disorder? And why now?. Neuropharmacology. 10.1016/j.neuropharm.2017.11.004
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7 May - Psychedelics, Nature & Mental Health with Sam Gandy

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