<scp> <i>CYP2C19</i> </scp> Genotype is Associated with Citalopram Treatment Outcomes in a Real‐World Setting

) and this association was replicated in 220 escitalopram users (P = 0.042). Furthermore, higher BMP2K variant burden significantly correlated with lower maintenance dose. These findings provide the first report of a U-shaped association between CYP2C19 metabolizer status and citalopram therapeutic outcomes and pinpoint BMP2K as a novel candidate gene with potential contribution to interindividual differences in citalopram response. Collectively, these results demonstrate that CYP2C19 genotype is significantly associated with citalopram outcomes in a real-world setting in which patient treatment was not guided by pharmacogenetics, thus avoiding open-label awareness, eliminating expectation bias of genetic testing and highlighting the value of large-scale biobank data for advancing precision psychiatry.