There is a renewed interest in psychedelic drugs as potential therapeutic agents for the treatment of psychiatric disorders. In particular, psilocybin has shown promise for the treatment of refractory depression 1 and major depressive disorder 2, and has also been explored as a treatment for tobacco and alcohol abuse 3, 4. However, despite suggestive evidenc...
Classical serotonergic psychedelics such as lysergic acid diethylamide or the naturally occurring compounds psilocybin and mescaline produce profound changes in mood, thought, intuition, sensory perception, the experience of time and space, and even the experience of self. Research examining psychedelic compounds has had a complex and turbulent evolution. Ma...
Clinical trials of psychedelics have provided support for their potential efficacy and safety. Although most combined a psychedelic with psychological support akin to psychotherapy, providing psychotherapy is costlier and more difficult to scale than providing only support to reduce harms. Trials with factorial designs can evaluate the individual effects of ...
Psychedelics as therapeutic agents have generated significant attention from clinicians and media sources in recent years. The authors provide an update to the psychiatric trainee on the evidence for psychedelics in the treatment of major depressive disorder and treatment-resistant depression. Many modern clinical trials of the classic, serotonergic psychede...
Natural psychedelic compounds are emerging as potential novel therapeutics in psychiatry. This review will discuss how natural psychedelics exert their neurobiological therapeutic effects, and how different neurotransmission systems mediate the effects of these compounds. Further, current therapeutic strategies for depression, and novel mechanism of action o...
Fungi produce diverse metabolites that can have antimicrobial, antifungal, antifeedant, or psychoactive properties. Among these metabolites are the tryptamine-derived compounds psilocybin, its precursors, and natural derivatives (collectively referred to as psiloids), which have played significant roles in human society and culture. The high allocation of ni...
Clinical studies provide evidence that ketamine and psilocybin could be used as fast-acting antidepressants, though their mechanisms and toxicity are still not fully understood. To address this issue, we have examined the effect of a single administration of ketamine and psilocybin on the extracellular levels of neurotransmitters in the rat frontal cortex an...
Psilocybin has been shown to be a powerful, long-lasting antidepressant in human clinical trials and in rodent models. Although rodents have commonly been used to model psychiatric disorders, Drosophila have neurotransmitter systems similar to mammals and many comparable brain structures involved in similar behaviors. The forced swim test (FST), which has be...
Drugs that target the human serotonin 2A receptor (5-HT2AR) are used to treat neuropsychiatric diseases; however, many have hallucinogenic effects, hampering their use. Here, we present structures of 5-HT2AR complexed with the psychedelic drugs psilocin (the active metabolite of psilocybin) and d-lysergic acid diethylamide (LSD), as well as the endogenous ne...
Obsessive-Compulsive Disorder (OCD) is a chronic psychiatric anxiety disorder distinguished by obsessive thoughts and repetitious actions. Current therapies for OCD are not very effective and have many possible side-effects. Psychedelics are a class of Schedule I substances that are re-emerging as novel therapeutics for a variety of psychiatric conditions. T...
Rapid-acting antidepressants disprove the dogma that antidepressants need several weeks to become clinically effective. Ketamine, the prototype of a rapid-acting antidepressant, is an N-methyl-D-aspartate (NMDA) receptor blocking agent. A single i.v. application of ketamine induces rapid changes in glutamatergic neurotransmitter systems, leading to preferent...
Mounting evidence suggests safety and efficacy of psychedelic compounds as potential novel therapeutics in psychiatry. Ketamine has been approved by the Food and Drug Administration in a new class of antidepressants, and 3,4-methylenedioxymethamphetamine (MDMA) is undergoing phase III clinical trials for post-traumatic stress disorder. Psilocybin and lysergi...
Our creativity is challenged daily when facing new situations asking for novel solutions. Creativity, a multicomponent construct includes flexible divergent and rigid convergent thinking. Psychedelic drugs like psilocybin can enhance creativity and affect state of mind (mood, empathy, openness). Of note, flexible thinking is disturbed in psychopathological c...
Research on psychedelics has generated renewed interest over the past decade. Recent pilot studies have shown safety and feasibility of psilocybin, a naturally occurring psychedelic, as a therapeutic tool for treating mood and substance use disorders, including tobacco and alcohol addiction. Findings from laboratory research indicate that psychedelics, when ...
The neurobiology of synaesthesia is receiving growing attention in the search for insights into consciousness, such as the binding problem. One way of decoding the neurocognitive mechanisms underlying this phenomenon is to investigate the induction of synaesthesia via neurochemical agents, as commonly occurs with psychedelic substances. How synaesthesia is a...
In this dissertation, I used theories of serotonin to understand the effects of serotonergic hallucinogens on visual perception and attention. I began by studying hallucinatory syndromes in drug users in Chapter 1. Despite long-standing reports of prolonged or reoccurring perceptual changes in a subset of hallucinogen users, very little is known about Halluc...
Pyramidal neurons in layer 5 of the cerebral cortex are involved in learning and memory and have complex connections with other neurons through a very large array of dendrites. These dendrites can switch between long term depression and long term potentiation depending on global summation of various inputs. The plasticity of the input into pyramidal neurons ...
Activation of 5-HT(2A) receptors is thought to mediate the hallucinogenic effects of LSD. Nevertheless, in a previous report we provided evidence that a delayed temporal phase of the behavioral pharmacology of LSD is mediated by D(2)-like dopamine receptor stimulation. In this study rats were trained to discriminate LSD with either a 30 min preinjection time...
To date, there is no doubt that dopamine plays a key role in the behavioural disorders associated with schizophrenia. However, dopamine is not the only neurotransmitter involved in this syndrome, as it interacts with many neuronal systems in brain. Of special interest is the interaction between dopaminergic and serotoninergic systems with evidence from pharm...
