OPEN Foundation

H. Curran

Psychedelics and related drugs: therapeutic possibilities, mechanisms and regulation


The word “psychedelic” derives from the Greek terms for mind—psyche—and “delos” which means “clear, manifest,” so in essence, psychedelic drugs can be seen as the prototype “window on the mind” concept. The term was originally coined in the 1950s to describe lysergic acid diethylamide (LSD), mescaline, and other hallucinogens, drugs that profoundly alter human experience. These have subsequently been shown to act primarily as agonists at the 5-HT2Areceptor in the brain. Research into the therapeutic potential and mechanisms of action of psychedelic and related drugs peaked in the late 1960s but then stagnated for 50 years after the 1971 UN Psychotropics Convention made psychedelic research with humans almost impossible to carry out (Kyzar et al. 2017).

Recently, however, this area is experiencing a renaissance as drugs often associated with recreational use—such as LSD, ketamine, and cannabis/cannabinoids—have been shown to have therapeutic potential in a range of disorders such as treatment-resistant depression, suicidal ideation, and some pediatric epilepsies. Further, recent pilot studies suggest that MDMA as well as the classic psychedelics, LSD, and psilocybin may contribute to the pharmacopeia for post-traumatic stress disorder (PTSD) and other difficult-to-treat psychiatric disorders. Research has also been stimulated by functional neuroimaging studies of single doses of psychedelics showing that they produce widespread changes in brain connectivity as well as profound alterations to perception and cognition. At the same time, as one would expect from a relatively fledgling area, many questions remain about mechanisms of action, safety, and efficacy. These include what type of psychological therapies best combine with which type of psychedelic drug, whether some types of drug have benefits even without psychological treatment, what the optimal doses are, from single dose through to intermittent or repeated dosing. The current renaissance in empirical psychedelic research stimulated this Special Issue of Psychopharmacology. The articles are grouped into three sections: Clinical efficacy and clinical issues; Effects and Mechanisms of action; Regulation and history.

Curran, H. V., Nutt, D., & de Wit, H. (2018). Psychedelics and related drugs: therapeutic possibilities, mechanisms and regulation. 10.1007/s00213-017-4822-3
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Effects of ecstasy on cooperative behaviour and perception of trustworthiness: A naturalistic study


Background: Acute recreational use of 3,4-methylenedioxymethamphetamine (MDMA; ‘ecstasy’) can promote pro-social effects which may alter interpersonal perceptions.

Aims: To explore such effects, this study investigated whether acute recreational use of ecstasy was associated with changes in individual perception of trustworthiness of people’s faces and co-operative behaviours.

Method: An independent group, repeated measures design was used in which 17 ecstasy users were tested on the night of drug use (day 0) and again three days later (day 3); 22 controls were tested on parallel days. On each day, participants rated the trustworthiness of 66 faces, carried out three co-operative behaviour tasks (public good; dictator; ultimatum game) and completed mood self-ratings.

Results: Acute ecstasy use was associated with increased face trustworthiness ratings and increased cooperative behaviour on the dictator and ultimatum games; on day 3 there were no group differences on any task. Self-ratings showed the standard acute ecstasy effects (euphoria, energy, jaw clenching) with negative effects (less empathy, compassion, more distrust, hostility) emerging on day 3.

Conclusions: Our findings of increased perceived trustworthiness and co-operative behaviours following use of ecstasy suggest that a single dose of the drug enhances aspects of empathy. This may in turn contribute to its popularity as a recreational drug and potentially to its enhancement of the therapeutic alliance in psychotherapy.

Stewart, L. H., Ferguson, B., Morgan, C. J. A., Swaboda, N., Jones, L., Fenton, R., … & Curran, H. V. (2014). Effects of ecstasy on cooperative behaviour and perception of trustworthiness: A naturalistic study. Journal of Psychopharmacology, 28(11), 1001-1008.

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21 March - Ketamine Discussion with Celia Morgan, Filip Tylš & Will Barone