CYP2C19 and major depressive disorder: Hahn and Roll (2022) evaluated the clinical utility of CYP2D6 and CYP2C19 pharmacogenetics by comparing the proportion of actionable genotypes (genotypes with recommendations other than ‘initiate or treat with standard dose’) before and after pharmacogenetic testing service (Hahn and Roll, 2022). Separately, in a large Danish population-based case cohort of patients with mental disorders including depression (N = 51,464), 27% of the cases were reported with CYP2D6 and CYP2C19 NM phenotypes (Lunenburg et al., 2021).