Lysergic acid diethylamide (LSD) alters brain activity in networks and structures involved in music processing, but these effects are largely unchanged by listening to music. In a functional magnetic resonance imaging study of 51 healthy participants given either 100 µg of LSD or a placebo, LSD reduced connectivity within the default mode and visual networks while increasing connectivity between various networks. It also altered functional connectivity of limbic and cortical structures related to music-induced emotion and decreased low-frequency oscillations in the occipital lobe and default mode network. Significant effects of music occurred only in the auditory cortex, and prior findings on music and psychedelics could not be replicated.
Lysergic acid diethylamide (LSD) increases global cerebral blood flow and internal carotid artery flow without affecting artery diameter, effects opposite to those of psilocybin. Functional connectivity analyses show decreases in global connectivity (GCOR), which is negatively correlated with the increase in cerebral blood flow. An anticlockwise hysteresis loop between plasma drug levels and subjective effects suggests atypical pharmacodynamic mechanisms. These findings, derived from simultaneous PET-MRI in seven healthy volunteers, establish the dose-occupancy relation of LSD at cerebral serotonin 2A receptors and highlight neurophysiological differences from related psychedelics, providing insights for clinical development.