medRxiv : the preprint server for health sciences
March 11, 2025
Kaoru Nashiro, B Rael Cahn, Paul Choi et al.
2 citations
preprint
A week of daily mindfulness meditation with slow breathing lowered blood levels of amyloid beta, a protein linked to Alzheimer's disease, while the same practice with normal breathing raised those levels. A control group that did not meditate showed no change. The results suggest that slow breathing may be a mechanism through which meditation influences biological pathways relevant to Alzheimer's disease.
medRxiv : the preprint server for health sciences
October 21, 2024
Pascal Grumbach, Jan Kasper, Joerg F Hipp et al.
1 citation
preprint
Autism spectrum disorder involves altered resting-state brain function, and an imbalance between excitation and inhibition is a proposed mechanism. In two large independent cohorts, individuals with autism consistently showed reduced local brain activity in default mode network nodes and increased activity in temporal regions, cerebellum, and brainstem. These activity changes spatially overlapped with multiple neurotransmitter systems, including dopamine, glutamate, GABA, and acetylcholine. The NMDA-antagonist ketamine, but not the GABA-potentiator midazolam, induced activity changes resembling those seen in autism, suggesting that pharmacologically shifting the excitation-inhibition balance can mimic autism-related brain alterations.
medRxiv : the preprint server for health sciences
January 16, 2026
Colleen Caleshu, Maryann Campion, Jehannine J Austin et al.
Mindfulness meditation may reduce burnout and stress among genetic counselors. In a randomized controlled trial with 397 clinical genetic counselors in the US, those assigned to 10 minutes of daily app-based mindfulness meditation for eight weeks showed lower burnout and stress compared to a no-meditation control group. The effect on burnout was large. However, the active control meditation designed to mimic mindfulness without its techniques did not perform as an inert control, so the primary comparison between mindfulness and active control was inconclusive. Further research with more diverse samples and better controls is needed.
medRxiv : the preprint server for health sciences
May 27, 2025
Colin G Walsh, Michael Ripperger, Thomas H McCoy et al.
preprint
Predicting which people with major depressive disorder will develop treatment-resistant depression from electronic health record data alone is not yet accurate enough for clinical use. Models built using sociodemographic features, medications, and diagnosis codes from three large U.S. health systems performed only slightly better than chance, with discrimination scores (AUROC) between 0.58 and 0.64 within the same health system and dropping to 0.51–0.58 when applied to a different system. Agreement between models from different sites was low, with concordance correlation coefficients ranging from 0.13 to 0.38. Age and sex were the most important features driving differences in model predictions. The findings suggest that readily available electronic health record data are insufficient for reliable prediction and that further improvement will require additional data types.
medRxiv : the preprint server for health sciences
January 18, 2025
preprint
Among critically ill adults undergoing emergency tracheal intubation, it is uncertain whether the choice of ketamine or etomidate for induction of anesthesia affects patient outcomes. The Randomized trial of Sedative choice for Intubation (RSI) is a pragmatic, multicenter trial enrolling 2,364 patients across 14 U.S. sites to compare ketamine versus etomidate. The primary outcome is all-cause, 28-day in-hospital mortality; a secondary outcome is cardiovascular collapse during intubation. Enrollment began in April 2022 and is expected to conclude in 2025. Prespecifying the protocol and statistical analysis plan before enrollment ends increases the trial's rigor, reproducibility, and transparency.
medRxiv : the preprint server for health sciences
November 2, 2024
Theresa R Lii, Josephine R Flohr, Robin L Okada et al.
preprint
The placebo antidepressant response was weaker in depressed patients who were already taking opioid medications, independent of their pain levels. In a re-analysis of a randomized trial, patients on chronic opioid therapy who received a placebo showed depression scores 10 points higher on the Montgomery-Åsberg Depression Rating Scale (MADRS) across 1 to 14 days after treatment, indicating less improvement. When measured as percent change, opioid users experienced 38.4% less improvement than non-users. For patients who received ketamine, baseline opioid use did not significantly affect depression scores. Pain intensity did not predict depression outcomes, and the link between depression and pain was negligible. These results come from a small, unregistered post hoc analysis and require confirmation.