Real-World Characterization of Psychiatric Pharmacogenomic Test Ordering and Clinical Relevance in Adults and Children

Pharmacogenomic (PGx) testing is increasingly utilized to guide psychiatric medication selection and dosing, yet real-world characterizations of test ordering and clinical implications remain understudied. Additionally, the extent to which psychiatry-focused PGx results inform prescribing beyond mental health medications is unclear. This study examined patterns of psychiatry-focused PGx test ordering, the clinical relevance of results among adult and pediatric patients, and implementation challenges within a large health system. Electronic health records (EHRs) of 3383 individuals undergoing psychiatry-focused PGx testing between 2013 and 2023 were analyzed. Test reports, available as unstructured PDFs, required manual curation before merging with clinical data. Demographic characteristics, test ordering patterns, genotype distributions, and drug-gene interactions (DGIs) were assessed. Results indicated that 94.5% of individuals had one or more clinically actionable PGx variants. DGIs were identified for current psychiatric medications in 19.3% of adults and 15.0% of youth. Additionally, non-psychiatric DGIs were identified in 11.8% of adults and 2.1% of youth. Most patients had genotype profiles that could guide future psychiatric and non-psychiatric prescribing. Despite the clinical relevance, PGx results were inconsistently integrated into EHRs, limiting accessibility and reuse. Indicators of disparities in test ordering related to gender and race suggested systemic inequities and variability in provider adoption practices. Psychiatry-focused PGx testing holds substantial potential to optimize current and future medication prescribing, extending beyond psychiatry. Key challenges include fragmented EHR integration, inconsistent provider adoption, and disparities in test ordering. Improved standardized reporting, structured EHR integration, and enhanced provider education are necessary to maximize PGx benefits in patient care.