Psychedelic drugs like LSD acutely reduce low-frequency electrical activity across the brain in rats, but these changes return to baseline after 24 hours. However, brain stimulation applied 24 hours after LSD—a period of heightened neuroplasticity—produces larger and distinct shifts in brain activity compared with stimulation alone. This suggests that even after the acute effects of LSD have faded, latent effects remain that can interact with brain stimulation to alter brain states. These proof-of-concept findings indicate that psychedelic drugs could work in combination with brain stimulation to achieve enhanced effects on brain activity, with future studies needed to assess impacts on behavior.
Lysergic acid diethylamide (LSD) acutely reduces low-frequency electrical activity across the brain in rats, an effect that returns to normal after 24 hours. However, brain stimulation applied during a window of heightened neuroplasticity 24 hours after LSD produces larger and distinct changes in brain activity compared to stimulation after a placebo. This proof-of-concept finding suggests that psychedelic drugs may work in combination with brain stimulation to achieve enhanced effects on brain activity, with future work needed to assess impacts on behavior.
In a pilot study, patients with schizophrenia and cannabis use disorder showed over-connectivity in the default mode network (DMN) at rest, which correlated with more severe positive symptoms, and reduced anticorrelation between the DMN and the executive control network (ECN). After smoking a 3.6% THC cannabis cigarette or ingesting a 15 mg THC pill, DMN hyperconnectivity decreased and DMN-ECN anticorrelation increased. The degree of anticorrelation in healthy controls and in patients after cannabinoid administration positively correlated with working memory performance. The results suggest that DMN connectivity can change, which may inform future treatments targeting circuit-level dysfunction.