Psilocybin restores cognitive function and synaptic density in an Alzheimer's mouse model, with stronger gains after low-dose treatment before plaque onset

Psilocybin improved memory, learning, and brain connectivity in a mouse model of Alzheimer's disease, with the strongest effects appearing when low doses were given before major amyloid plaque buildup. The treatment increased synaptic density in the hippocampus and cortex and reversed several cognitive deficits linked to the disease. The findings point to timing and dose as critical factors. Lower-dose psilocybin outperformed a higher dose in animals treated earlier in disease progression, while later treatment still produced measurable but weaker benefits. Researchers also reported changes in amyloid burden and neuroinflammatory markers, suggesting that psilocybin's effects may extend beyond symptom relief to mechanisms involved in degeneration. Alzheimer's pathology destroys synapses long before widespread neuron loss, making compounds that promote plasticity especially relevant. Psilocybin's known capacity to drive structural and functional neural remodeling positions it as a candidate for future translational work, although the results come from mice and do not yet establish efficacy or safety in people with Alzheimer's disease.