Parsing Specificity in Psychiatric Polygenic Scores—What the p-Factor Adds and What It Does Not

confront a central ambiguity in psychiatric genetics.They ask, how much of what polygenic scores (PGSs) estimate is associated with disorder-specific risk vs a transdiagnostic general factor of psychopathology (p)?This latent dimension, estimated with genomic structural equation modeling (genomic SEM), captures shared genetic liability across disorders and is analogous to the g factor in cognitive research.In approximately 6000 young adults from the Twins Early Development Study (TEDS), Keser et al 1 compare uncorrected disorder PGS, a p-factor, and p-corrected (non-p)PGSs.A clear pattern emerges: For matched symptom domains, the p PGS derived from 11 major psychiatric disorders showed more pronounced associations (mean β of approximately 0.11 vs 0.07 for disorder PGSs), whereas for self-reported diagnoses, p and uncorrected PGSs had broadly similar