Fig. 3: Hierarchical index in psychedelic and psychotic brains.

a LSD effects on the hierarchical index across 15 healthy volunteers. fMRI images were scanned three times for each condition of LSD administration and a placebo. During the first and third scans, the subjects were in an eye-closed resting-state; during the second scan, the subjects were simultaneously exposed to music. A triangle (12 of 15 subjects) indicates that the hierarchical indices were higher across three runs during the LSD administration than in the placebo condition. b Left: relationship between the hierarchical index and BPRS positive symptoms across 133 individuals with either ADHD, schizophrenia, or bipolar disorder (r = 0.276, P = 0.0012, two-sided unadjusted Spearman correlation). The error band represents the 95% confidence interval of the regression estimate. Right: correlation between the hierarchical index and each item in BPRS positive symptoms (*P < 0.05, **P < 0.01, two-sided unadjusted Spearman correlation; see Source Data for specific r and P values). c Left: the hierarchical index across different clinical groups from the UCLA dataset (SZ schizophrenia, n = 47; BP bipolar disorder, n = 45; ADHD attention-deficit/hyperactivity disorder, n = 41; HC healthy control, n = 117); right: the hierarchical index across individuals with schizophrenia (n = 92) and healthy control (n = 98) from the PKU6 dataset. In each box plot, the midline represents the median, and its lower and upper edges represent the first and third quartiles, and whiskers represent the 1.5 × interquartile range. *P < 0.05, **P < 0.01, two-tailed two-sample t-test. Source data are provided as a Source Data file.