Title:Psychedelics and Hallucinogens in Psychiatry: Finding New Pharmacological
Targets
Volume: 22
Issue: 15
Author(s): Teresa Reynolds Sousa*, João Rema, Sergio Machado and Filipa Novais
Affiliation:
- Psychiatry and Mental Health Department, North Lisbon Hospital Centre, Lisbon, Portugal
Keywords:
Psychedelics, LSD, Psilocybin, Ayahuasca, DMT, Psychiatry, Depression, Anxiety, Substance use, Obsessive-compulsive.
Abstract:
Background: The therapeutic options for neurobehavioral disorders are still limited, and
in many cases, they lack a satisfactory balance between efficacy and side effects.
Objectives: This work aims to review current evidence regarding the potential contribution of
psychedelics and hallucinogens to the discovery of new drugs for treating different psychiatric disorders.
Discussion: Ayahuasca/N,N-dimethyltryptamine (DMT), lysergic acid diethylamide (LSD), and
psilocybin have evidence supporting their use in depression, and psilocybin and ayahuasca have also
shown good results in treatment-resistant depression. In randomized controlled trials (RCTs)
conducted with anxious patients, there were symptomatic improvements with psilocybin and LSD.
Psilocybin diminished Yale-Brown Obsessive Compulsive Scale (Y-BOCS) scores in a small obsessive-
compulsive disorder (OCD) sample. The evidence is less robust regarding substance use disorders,
but it suggests a possible role for LSD and psilocybin in alcohol use disorders and for
psilocybin in tobacco addiction. In a clinical setting, these substances seem to be safe and well-tolerated.
Their mechanisms of action are not fully elucidated, but there seems to be a preponderant
role of 5-hydroxytryptamine (5HT) 2A agonism, as well as connectivity changes within the default
mode network (DMN) and amygdala and some other molecular modifications.
Conclusion: The studies underlying the conclusions have small samples and are heterogeneous in
their methods. However, the results suggest that the use of psychedelics and hallucinogens could
be considered in some disorders. More studies are needed to reinforce their evidence as potential
new drugs.