A team of researchers from McGill University’s Department of Biomedical Engineering and the Montreal Neurological Institute Hospital in association with the Broad Institute at Harvard/MIT, SUNY Downstate Health Sciences University, and Mila – Quebec Artificial Intelligence Institute have demonstrated how psychedelic-induced changes in conscious awareness are rooted in specific neurotransmitter receptor systems.
While there is still much to understand about how specific psychedelics drugs alter states of consciousness, this first-of-its-kind study provides important information for clinical researchers and neuroscientists interested in how these drugs may be beneficial as therapies for several disorders including schizophrenia and depression.
The study focused on testimonials of 6,850 individuals who had taken a variety of 27 different drugs. Using a machine learning approach, they were able to extract commonly used words from the subjects’ reports and link them with the neurotransmitter systems responsible. The team was then able to map the subjective experiences of the subjects with the brain regions where the receptors are most frequently located. These areas turned out to be located in the deepest parts of processing centers of the brain.
Designing drugs to create specific mental states
One goal of researchers working in the area of psychedelics is to create hallucinogenic drug compounds that can reliable produce desired mental states. This research supports this effort. By using thousands of gene transcription probes, the team was able to render a 3D map of the brain receptors with specific subjective experiences mapped to them. While psychedelic experience is often highly personal and varies between individuals, the large dataset allowed the researches to reliably characterize coherent states of consciousness across individuals.
An example of how psychedelics might be used as a psychiatric intervention involves the feeling of self detachment known as ego dissolution. The study found that this feeling was most associated with the receptor serotonin 5-HT2A. However, other serotonin receptors (5-HT2C, 5-HT1A, 5-HT2B), adrenergic receptors Alpha-2A and Beta-2, as well as the D2 receptor were also identified. Using drugs that target these receptors may be able to reliably create this feeling among patients that may benefit from it.
“Hallucinogenic drugs may very well turn out to be the next big thing to improve clinical care of major mental health conditions,” according to lead author Professor Danilo Bzdok, “Our study provides a first step, a proof of principle that we may be able to build machine learning systems in the future that can accurately predict which neurotransmitter receptor combinations need to be stimulated to induce a specific state of conscious experience in a given person.”