Ketamine, a drug that blocks N-methyl-D-aspartate receptors, produces rapid and lasting antidepressant effects in people with major depressive disorder and in animal models, but its use is limited by side effects like dissociation and psychosis-like experiences. The drug may work by enhancing signaling through another receptor type, AMPA receptors, in brain cells, possibly by reducing inhibition or blocking spontaneous NMDAR activity. It also activates pathways linked to brain plasticity and synapse formation, such as BDNF/TrkB and mTOR signaling. These processes may help restore the balance of excitatory and inhibitory signals in brain circuits disrupted in depression. Understanding these mechanisms could guide development of safer, more effective treatments.
A brain-computer interface-based mindfulness meditation app, delivered alongside radiofrequency catheter ablation for atrial fibrillation, significantly reduced patients' pain, anxiety, and fatigue compared to conventional care alone. In a randomized trial of 84 patients, those using the app reported lower numeric rating scale scores (mean 4.6 vs 5.7), lower State Anxiety Inventory scores (mean 36.7 vs 42.3), and lower Brief Fatigue Inventory scores (mean 3.4 vs 4.7). The app also reduced the dose of fentanyl needed during the procedure (mean 3.96 vs 4.85 mcg/kg), though heart rate, blood pressure, oxygen levels, and other sedative use did not differ between groups.