Several groups, including the Dutch Pharmacogenetic Working Group (DPWG) and the Clinical Pharmacogenetics Implementation Consortium, have formulated pharmacogenetic dosing guidelines, including for drugs for psychosis and depression, and (among other pharmacogenes) CYP2D6 (Beunk et al., 2023; Brouwer et al., 2022). This evidence concerns the gene CYP2D6 and psychotic disorder.