People with anorexia nervosa or bulimia nervosa report anomalous self-experiences (ASEs) at levels comparable to those seen in schizophrenia. In a study of 90 individuals with anorexia, 41 with bulimia, and 92 general-population controls, ASEs were strongly correlated with feeling extraneous from one's own body, body uneasiness, and eating-disorder symptoms. Statistical modeling showed that ASEs influence eating-disorder symptoms indirectly, through disturbances in embodiment, identity, and body image. The findings suggest that anomalous interoceptive processes may initiate a maladaptive cascade that impairs embodiment and selfhood in feeding and eating disorders, and that assessing ASEs could help identify an early shared vulnerability across severe disorders involving altered embodiment.
Lysergic acid diethylamide (LSD) reduces local brain activity and connectivity in sensory and association regions, with effects linked to specific neurotransmitter receptors. In 15 healthy adults, fMRI scans under LSD versus placebo showed decreased amplitude of low-frequency fluctuations (ALFF) in somatosensory, visual, default mode, and frontoparietal networks, and decreased regional homogeneity (ReHo) in sensory and subcortical areas. Test-retest reliability was high for ALFF and moderate for ReHo. LSD-induced changes correlated negatively with densities of D2 and 5-HT1A receptors, suggesting the drug engages neurochemical processes beyond its primary 5-HT2A target. These preliminary results indicate complex, dynamic mechanisms underlying LSD's neural effects.