Psilocybin, a classic hallucinogen produced by over 100 mushroom species, binds strongly to serotonin receptors in brain regions like the cerebral cortex and thalamus. Since 1992 legislation enabled more research, studies have explored its effects on depressed mood, anxiety disorders, obsessive-compulsive disorder, alcohol use disorder, and tobacco use disorder. This article reviews the design and results of those studies and discusses psilocybin's potential clinical applications.
Ayahuasca, a traditional psychoactive sacrament used for centuries in Amazonian shamanic rituals, produces its psychedelic effects through the combination of monoamine oxidase inhibitors (MAOIs) from the Banisteriopsis caapi vine and N-N-dimethyltryptamine from Psychotria viridis or Diplopterys cabrerana. Its ritual use has recently increased, drawing attention for potential treatment of mental illnesses like substance use and depressive disorders. However, its MAOI properties raise concerns about serious drug interactions in patients. This paper describes ayahuasca's pharmacology, potential drug interactions, and clinical data on its therapeutic potential in psychiatric illness.
Intranasal esketamine, FDA-approved for treatment-resistant depression and major depressive disorder with suicidal ideation, has not been studied in bipolar disorder. Antidepressants can induce rapid cycling in bipolar patients, but this case report suggests that intranasal esketamine combined with mood stabilizer therapy may be safe for a bipolar patient without recent manic or hypomanic episodes.