The past decade brought the beginnings of a renaissance in research on psychedelic drugs. Two articles in this issue of Biological Psychiatry signify that the resurrection of this longignored topic has begun to mature and bear at least the promise of fruit. In the early 1970s, the onset of the “War on Drugs” brought with it a near-total hiatus in serious research on psychedelic drugs, especiall...

Visual illusions and hallucinations are hallmarks of serotonergic hallucinogen-induced altered states of consciousness. Although the serotonergic hallucinogen psilocybin activates multiple serotonin (5-HT) receptors, recent evidence suggests that activation of 5-HT2A receptors may lead to the formation of visual hallucinations by increasing cortical excitability and altering visual-evoked corti...

Emotional face processing is critically modulated by the serotonergic system. For instance, emotional face processing is impaired by acute psilocybin administration, a serotonin (5-HT) 1A and 2A receptor agonist. However, the spatiotemporal brain mechanisms underlying these modulations are poorly understood. Here, we investigated the spatiotemporal brain dynamics underlying psilocybin-induced m...

Two recent studies report changes in human brain responses after exposure to psilocybin, the active ingredient of hallucinogenic mushrooms. Psilocybin increased sensory cortex responses during emotional recollection, but decreased resting-state blood flow in prefrontal cortex, with potential implications for treating depression.

Mycelial cultures of PSILOCYBE CUBENSIS, with the ability to form psilocybin and psilocin DE-NOVO, also hydroxylated and methylated fed tryptamine to give psilocin in up to 3.3% dry mass of the obtained fruit bodies. By using HPLC and TLC, it was found that these mushrooms contain only a small amount of psilocybin (0.01-0.2% dry mass). The values of psilocin are the highest described in any mus...

Psilocybin has been used for centuries for religious purposes; however, little is known scientifically about its long-term effects. We previously reported the effects of a double-blind study evaluating the psychological effects of a high psilocybin dose. This report presents the 14-month follow-up and examines the relationship of the follow-up results to data obtained at screening and on drug s...

BACKGROUND This report documents the phenomenology of the subjective experiences of 15 healthy psychedelic experienced volunteers who were involved in a functional magnetic resonance imaging (fMRI) study that was designed to image the brain effects of intravenous psilocybin. METHODS The participants underwent a semi-structured interview exploring the effects of psilocybin in the MRI scanner. ...

Research on the clinical applications of psychedelic-assisted psychotherapy has demonstrated promising early results for treatment of alcohol dependence. Detailed description of the content and methods of psychedelic-assisted psychotherapy, as it is conducted in clinical settings, is scarce. Methods: An open-label pilot (proof-of-concept) study of psilocybin-assisted treatment of alcohol depend...

Mushroom-forming fungi produce a wide array of toxic alkaloids. However, evolutionary analyses aimed at exploring the evolution of muscarine, a toxin that stimulates the parasympathetic nervous system, and psilocybin, a hallucinogen, have never been performed. The known taxonomic distribution of muscarine within the Inocybaceae is limited, based only on assays of species from temperate regions ...