A first-of-its kind study has cast new light on the biological mechanisms that could explain the dissolution of the ego experienced by people under the influence of the powerful psychedelic substance psilocybin.
Like other psychedelics, psilocybin—which is found in hallucinogenic mushrooms—can induce profoundly altered states of consciousness, including a phenomenon known as “ego-death, -loss or -dissolution” where one’s normal subjective experience of oneself melts away.
Evidence is emerging that an important neurotransmitter in the brain known as glutamate may play a role in the hallucinogenic effects of psychedelic substances, such as psilocybin. Neurotransmitters are chemical messengers that transmit signals throughout the brain and nervous system.
However, the activity of the glutamate system when it comes to the action of psilocybin on the brain and behavior of tripping individuals has never actually been tested in humans.
To address this gap in our knowledge, a team led by researchers from Maastricht University in the Netherlands conducted a double-blind, placebo-controlled trial to examine what happens to an person’s glutamate levels when they are under the influence of psilocybin.
They did this by monitoring the brains of 60 participants using magnetic resonance imaging (MRI,) finding significant alterations in glutamate that could be linked to experiences of ego death in the individuals involved.
According to a study published in the journal Neuropsychopharmacology, they found higher levels of glutamate in an area of the brain known as the prefrontal cortex, which were associated with negative experiences of ego dissolution.
Meanwhile, they observed lower levels of glutamate in another region in the brain called the hippocampus, which were associated with positive experiences of ego dissolution.
The prefrontal cortex is thought to be responsible for planning complex behavior, personality expression, decision-making and moderating social behavior, while the hippocampus is involved in the formation memories and has been linked to one’s sense of self-esteem, according to The Science of Psychotherapy.
It is still not clear how exactly how this brain activity could be linked to the dissolution of the ego. However, previous research has suggested that psychedelics affect certain regions of the brain in such a way that the individual temporarily loses access to autobiographical information, resulting in a breakdown of one’s personal identity.
“Our data add to this hypothesis, suggesting that modulations of hippocampal glutamate in particular may be a key mediator in the decoupling underlying feelings of (positive) ego dissolution,” the authors wrote in the study.
With growing interest in psychedelics as therapies for various mental disorders, such as depression and addiction, the latest results could have significant implications.
“Such findings provide further insights into the underlying neurobiological mechanisms of the psychedelic state, and importantly, provide a neurochemical basis for how these substances alter individuals’ sense of self, and may be giving rise to therapeutic effects witnessed in ongoing clinical trials the authors wrote,” the authors wrote in the study.