Distinct contributions of schizophrenia and neurotransmitter pathway genetic liability to neurocognition and antipsychotic efficacy in drug-naïve first-episode schizophrenia.

The genetic mechanisms underlying heterogeneity in symptom presentation and antipsychotic response in schizophrenia remain unclear, limiting the development of personalized treatment. We integrated genome-wide schizophrenia polygenic risk scores (SZ-PRS) and pathway-specific PRSs (pPRSs) for four major neurotransmitter systems to examine their associations with clinical phenotypes across the course of illness. Primary analyses were conducted in 394 drug-naïve, first-episode patients from the Chinese First-Episode Schizophrenia Trial (CNFEST) to investigate associations with baseline symptom severity, neurocognitive impairment, and longitudinal treatment response. The CNFEST cohort included 52-week longitudinal assessments of symptoms and neurocognition using the Positive and Negative Syndrome Scale and a modified version of the MATRICS Consensus Cognitive Battery. An independent case-control cohort evaluated associations with schizophrenia diagnosis, while a cohort of 514 healthy adults assessed whether PRS-cognition associations are specific to schizophrenia. Higher SZ-PRS predicted schizophrenia diagnosis (OR = 2.28, P