Penn Lifespan Informatics and Neuroimaging Center (PennLINC), Philadelphia, PA, United States; Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States.
2 papers in the library · 17 citations · publishing 2023-2024
A systematic review of 91 fMRI studies on acute psychedelic effects found substantial methodological heterogeneity. Only 51 unique samples were used across the 91 papers, and 54% of studies did not meet current standards for correcting Type I errors or controlling motion artifacts. Psilocybin and LSD consistently modulated connectivity along the sensorimotor-association cortical axis. Ketamine consistently increased activation in the dorsomedial prefrontal cortex. The review calls for future adoption of pre-registration, standardized processing and statistical testing, and data sharing to improve rigor.
Psychedelics such as psilocybin show promise for treating anxiety, but how they work is unclear. This review proposes a model where anxiety disorders involve the hippocampus biasing the amygdala and salience network toward anxiety-related information, creating a self-perpetuating cycle. Psychedelics temporarily free cortical networks from this hippocampal constraint, and increased plasticity afterward allows the hippocampus to integrate new information into a less biased contextual frame, reducing anxious thoughts. The model highlights that psychedelics can acutely increase anxiety, and future research should determine optimal treatment approaches informed by cognitive neuroscience.