A single high dose of psilocybin (25 mg) massively disrupts functional connectivity in the human brain, causing more than threefold greater change than methylphenidate (40 mg). These changes are driven by desynchronization across spatial scales, dissolving network distinctions by reducing correlations within and anticorrelations between networks. The strongest effects occur in the default mode network, which is connected to the anterior hippocampus and is thought to create the sense of space, time, and self. Individual differences in connectivity changes are strongly linked to the subjective psychedelic experience. A persistent decrease in connectivity between the anterior hippocampus and default mode network lasts for weeks, suggesting a neuroanatomical correlate of the therapeutic and proplasticity effects of psychedelics.
Analysis of post-marketing safety data for esketamine nasal spray, using four statistical methods on 5,132 adverse event reports from the FDA Adverse Event Reporting System (Q1 2019 to Q2 2023), identified dissociation, sedation, and hypertension as the most frequently observed adverse drug events. New rare signals were detected, including interstitial cystitis, substance abuse, and drug diversion. These findings may help healthcare professionals assess patient symptoms and identify risks during clinical use.