By Sanjukta Mondal

Psilocybin is a naturally occurring psychoactive compound found in mushrooms of the Psilocybe genus. These mushrooms may have existed on Earth for nearly 65 million years, dating to the asteroid impact that caused the dinosaurs' extinction. While Mesoamerican civilizations have used them for at least 3,000 years for therapeutic benefits, scientists have only recently begun investigating psilocybin and realizing its potential as a treatment for neurodegenerative and other brain-related disorders.

A recent study in Neuroscience set out to see whether a high dose of psilocybin could help patients with advanced Alzheimer's disease. The researchers focused on a woman in her 80s who had been living with Alzheimer's for 10 years and was given one oral dose of 5 grams of psilocybin-containing mushrooms. Soon after that single dose, she temporarily regained several abilities that had been lost years earlier because of her advanced condition.

She was able to talk and walk for longer periods, recognize some of her family members, and regain bladder control after five years of wearing diapers.

Regaining lost smile and memory

Alzheimer's disease (AD) is one of the most common forms of dementia and progressively worsens over time. It slowly takes away a person's ability to think, communicate and move freely, making even the simplest everyday tasks increasingly challenging. As the global population ages, cases of AD and other neurodegenerative disorders are rising with it. Most treatments currently available for Alzheimer's can, at best, help improve quality of life but do not offer meaningful functional recovery. Scientists have therefore broadened their search for promising therapeutic agents.

One such candidate is psilocybin, which activates specific serotonin receptors in the brain. Previous brain-scan studies investigating the effects of psychoactive compounds have shown increased communication between large-scale brain networks. In animal studies, these drugs have also been shown to promote neuroplasticity, which is the brain's ability to form new branches and connections between nerve cells.

To explore the effects of the mushroom compounds on AD, the researchers conducted an exploratory observational case report in which they closely followed one person to observe how she responded to the treatment. The woman involved in the study, 80, had been living with advanced Alzheimer's disease for 10 years. At the start of the study, she could barely speak, was unable to control her bladder and needed help walking. She was given a single oral dose of 5 grams of psilocybin-containing mushrooms, which is considered a high dose. A month later, she was given a slightly smaller dose of 3 grams.

They found that after taking a single high dose of psilocybin, the patient regained several abilities she had lost years earlier. Within 19 hours of taking the dose, she was able to hold hourlong conversations about her life, whereas before the study her speech had been limited to one or two words at a time. She began to show emotions and respond to humor.

Not only did her bladder control improve, but her diapers remained dry even overnight, and she also started dressing herself. She began to maintain eye contact and smile back at people. Many of the gains persisted for weeks, with some continuing after the second, lower dose.

This case showed that after receiving psilocybin, a patient with advanced Alzheimer's temporarily regained several abilities. The researchers, however, highlighted that the treatment did not reverse the disease but revealed that some functional abilities may still remain in the brain during late-stage Alzheimer's and can be temporarily reactivated under certain conditions.

Publication Details

Marcos Lago et al, Transient multidomain functional improvement in advanced Alzheimer's disease following high-dose psilocybin-containing mushroom administration: a case report, (2026). DOI: 10.3389/fnins.2026.1813281