Mushroom hallucinator alters brain networks for weeks

A recent study found that psilocybin, the active compound found in magic mushrooms, can cause temporary changes in brain networks associated with introspective thinking, such as daydreaming and memory. These effects last for weeks, suggesting that the brain may become more flexible and, as a result, improve people’s mental health.

The study opens up new possibilities for developing psilocybin-based therapies to treat depression and post-traumatic stress disorder. The study highlights the need for these drugs to be used under medical supervision, emphasizing that the changes induced in brain networks are not permanent but temporary, making them ideal for a potential drug. Users of psilocybin-containing mushrooms, commonly referred to as “magic mushrooms,” often report distorted perceptions of space, time, and self-perception.

Proponents of psychedelics have long argued that under the right conditions, these experiences can alleviate mental suffering. Some scientific studies support this theory, suggesting that psilocybin may have therapeutic benefits. Understanding exactly how this compound affects the brain is critical to effectively harnessing its therapeutic potential.

A study by researchers at Washington University School of Medicine in St. Louis found that psilocybin temporarily alters a critical network of brain regions involved in introspective thinking. The findings provide a neurobiological explanation for the drug’s hallucinogenic effects and could lay the groundwork for developing treatments for mental illnesses such as depression and post-traumatic stress disorder.

Dr. Nico W. F. Dosenbach, one of the study’s co-authors, explained that the initial effects of psilocybin are very powerful and, although they wear off, they leave a lasting impact. This effect is desirable in a potential drug because it does not aim to destroy a person’s brain networks, but it is not intended to immediately return everything to normal.

The study, published in the journal Nature, offers guidelines that other scientists can follow to assess the effects of psychoactive drugs on brain function. This could speed up the development of drugs for a variety of mental illnesses. In the 1950s and 1960s, psilocybin was considered a promising treatment for depression, but strict federal drug policies hampered further research. However, in recent years, regulations have relaxed, and interest in the field has been renewed.

The study’s first author, Joshua S. Siegel, MD, PhD, explained that while much is known about the psychological and molecular effects of psilocybin, little is known about its impact on functional brain networks. To fill this gap, Siegel assembled a team of experts, including Dosenbach and co-senior author Ginger E. Nichol, MD, PhD. Together, they developed a way to visualize the effects of psilocybin on participants’ functional brain networks and relate these changes to subjective experience.

The team recruited seven healthy adults who took high doses of psilocybin or methylphenidate in a controlled setting. Each participant was accompanied by trained experts who provided support throughout the experience. In addition, their brains were scanned using fMRI in the days and weeks before, during, and for three weeks after taking psilocybin.

The results showed that psilocybin caused profound and widespread changes in functional brain networks. Specifically, it desynchronized the default mode neural network, which is typically active when the brain is not doing anything specific. After losing synchronization, the network was restored, but small differences persisted for weeks.

The study found that the brains of people taking psilocybin were more similar to each other during the psychedelic experience than to their own brains before taking it. This suggests a temporary loss of individuality, a neurobiological confirmation of the sense of loss of self that users report.

Participants also rated their feelings of transcendence, connection, and awe, and a correlation was found between the magnitude of changes in functional networks and the intensity of the subjective experience.

Nichol, Siegel and Dosenbach caution that their study should not be interpreted as an excuse for the unsupervised use of psilocybin. The drug is not approved by the Food and Drug Administration (FDA) to treat depression or other conditions, and its use without the supervision of trained mental health professionals can be risky.

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