Psilocybin's Single-Dose Reactivation of Latent Circuits in Advanced Alzheimer's: Case Report Signals Neuroplastic Windows but Exposes Evidence Gaps

This n=1 observational case report from Frontiers in Neuroscience documents transient functional recovery in an 80-year-old woman with 10-year advanced Alzheimer's after 5 g psilocybin mushrooms, including extended speech, bladder control, and social engagement lasting weeks. As an uncontrolled case study with no blinding, randomization, or placebo, it ranks as very low-quality evidence prone to observer bias and natural fluctuation; no conflicts of interest were declared but generalizability is nil. The coverage underplays mechanistic context: psilocybin's 5-HT2A agonism disrupts rigid default-mode network connectivity while promoting BDNF-driven dendritic spine growth, as shown in RCT neuroimaging work (Carhart-Harris et al., PNAS 2012, n=15) and rodent plasticity assays (Ly et al., Cell Reports 2018). A 2023 systematic review in Translational Psychiatry (n=12 preclinical + 4 small human studies) notes similar network desynchronization could unmask residual circuits in late-stage dementia without reversing plaques. Mainstream accounts miss that gains faded after weeks, underscoring temporary disinhibition rather than disease modification, and ignore risks like cardiovascular strain in frail elderly patients.