Just a small amount of psilocybin, the bioactive component of so-called Mexican magic mushrooms, could have a positive impact on how we process emotions, according to University of Zurich researchers.
Emotions help individuals adjust to the environment and react to stress and strain, but are also needed for cognitive processes, physiological reactions and social behavior. They are linked to the part of the brain known as the limbic system, especially the amygdala.
These almond-shaped sections of the brain are involved in memory and decision-making, but also process negative emotions such as anxiety and fear. If they malfunction, negative signals are strengthened in the brain while positive ones are weakened, potentially leading to depression and anxiety disorders.
The researchers at the university’s psychiatric hospital have shown that psilocybin influences the amygdala by intervening specifically in this mechanism. The substance has a positive influence on healthy individuals because it exerts its effect via the serotonin system in the limbic brain regions.
Serotonin is a neurotransmitter, a sort of messenger in the brain, that helps regulate mood, appetite and sleep, as well as contributing to memory and learning.
The Zurich scientists were able to demonstrate in their study the effects of psilocybin using a technique known as functional magnetic resonance imaging that measures brain activity by detecting associated changes in blood flow.
“Even a moderate dose of psilocybin weakens the processing of negative stimuli by modifying amygdala activity in the limbic system as well as in other associated brain regions,” explained one of the lead researchers, Rainer Krähenmann, in a statement.
For the Zurich scientists, their study – which involved healthy volunteers - clearly shows that modulating amygdala activity using the psychoactive substance leads to an improved mood, a finding that could have clinical implications.
According to Krähenmann, depressed patients, who react more to negative stimuli and have more negative thoughts than most people, could potentially benefit from taking psilocybin. Further studies with those patients would be required though to see if the substance can positively affect their mood.
The researchers believe that substances such as psilocybin are worthy of being studied as current drugs used to treat depression and anxiety disorders are not always effective and can have unwanted side effects.
The resulty of the Zurich study are published in the latest edition of the journal Biological Psychiatry.
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