Compounds Being Studied for Use in Psychiatric Practice
ORLANDO, Fla.—The opening session of the 31st annual Psych Congress gave attendees a detailed view of how psychedelic compounds such as psilocybin and LSD affect the brain and the ways in which they could be used in psychiatric practice.
The hourlong talk was delivered by Robin Carhart-Harris, PhD, the head of psychedelic research for the center for neuropsychopharmacology at Imperial College London in England.
Psych Congress cochair Charles L. Raison, MD, who is also involved with psychedelic research, described Dr. Carhart-Harris as a “spectacular unique leader in this emerging world.”
“Robin has really been the leading light for the last more than half a decade, looking not just at what [psychedelics] mean clinically but what’s really important, looking much more at this translational science question of how can it be that something that people take one time can produce these long-term effects,” he said. “This is really a special treat for us at Psych Congress.”
Through research involving neuroimaging and other techniques, Dr. Carhart-Harris used psychedelics as “probes into, in many ways, what it means to be human,” Dr. Raison said.
“If you induce these profound experiences in a person’s consciousness, that digs very deeply into what a lot of us cherish in terms of what it means to be human, to have certain perceptions, to have certain feelings,” he added.
“The ability to study those, to induce those and look before and after, because the drugs serve as a probe into that world, is I think one of the greatest and most remarkable technologies that we have at our disposal currently to understand how the brain, the mind, the heart, the spirit all come together.”
In his presentation, Dr. Carhart Harris also highlighted the fact that psychedelics seem to have enduring outcomes after just a single administration.
“As a drug model, that’s kind of unheard of, so what’s going on here?” he asked.
Dr. Carhart-Harris, who has studied both psychoanalysis and psychopharmacology, has been researching the use of psychedelics in humans since 2008, and as a depression treatment since 2011.
He said widespread interest in the topic began to develop in 2016, with the publication of studies from the Johns Hopkins University School of Medicine in Baltimore Maryland, and the New York University Langone Medical Center in New York City on the use of psychedelics for depression and anxiety in people with terminal cancer, which were hailed as potentially groundbreaking. Those studies followed other research demonstrating psychedelics helped increase well-being, reduce suicidality and symptoms of obsessive-compulsive disorder, and treat substance use disorders.
“This seems to be getting quite mainstream academic support,” he said.
For the last 2 years, Dr. Carhart-Harris has been working with London-based life sciences company Compass Pathways to develop psilocybin as a medicine. In October, the US Food and Drug Administration granted the Breakthrough Therapy designation to the company for the use of psilocybin as a therapy for treatment-resistant depression (TRD).
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“Things are really moving now,” he said.
Multi-site randomized controlled trials on the use of psilocybin for TRD will soon be underway in Europe and the United States, he said. At Imperial College, researchers will be conducting a trial comparing psilocybin and escitalopram as treatments for major depressive disorder.
“It’s really now putting this to the test, and hopefully in a couple years or so we’ll be able to know how it compares with a leading antidepressant,” Dr. Carhart-Harris said.
A PRECISE APPROACH
Past research has shown that psychedelics work on the body’s serotonin system, particularly on the 5-HT2A receptors, which are highly cortical, Dr. Carhart-Harris explained. Recent research with a positron emission tomography (PET) agonist tracer added to that knowledge, showing that the expression of 5-HT2A receptors is especially prominent in high-level cortical regions of the brain and regions associated with the default mode network, which is linked with such high-level functions as introspection and imagination.
“It’s intriguing that these compounds that can have such a profound effect on consciousness have their key locus of action in such a high-level aspect of the brain,” he said.
He noted that psychedelics have a relatively more precise psychopharmacological approach than antidepressants developed in recent decades.
“In a way we’re reinventing the wheel in the sense the psychedelics have been used as plant medicines for hundreds of years, perhaps even thousands of years by some cultures,” he said.
Dr. Carhart-Harris suggests that psychedelics work by relaxing aberrant beliefs which underlie a range of different psychopathologies, such as the pessimism common in depression. By inducing neural plasticity, they also provide a window of opportunity for revising those beliefs, he said.
Dr. Carhart-Harris argued that psychedelics are not addictive and are much more favorable in terms of toxicity than another emerging psychiatric treatment, ketamine. Users may experience headache, and about 5% have a residual effect on their perception, though only 1% are disturbed by it, he said. There have been concerns about psychedelics leading to psychotic episodes and disorders, but Dr. Carhart-Harris said that association is not supported by evidence.
“Psychedelics: therapeutic mechanisms & clinical findings.” Presented at Psych Congress 2018: Orlando, FL.; October 25, 2018.