PHARMACOGENOMIC-GUIDED PRESCRIBING IN MAJOR DEPRESSIVE DISORDER AND SCHIZOPHRENIA: A SYSTEMATIC REVIEW

Abstract

Introduction: Pharmacogenomic (PGx)-guided prescribing has been proposed to improve psychotropic medication selection by identifying clinically relevant gene–drug interactions. Evidence from controlled trials varies by diagnosis, outcome, and follow-up period. This review assessed PGx-guided prescribing compared with standard care, with particular attention to major depressive disorder (MDD) and schizophrenia. Methods: A systematic literature search was conducted in June 2026 across PubMed, Scopus, ProQuest, Taylor & Francis, Cochrane Library, and EBSCO for studies published from 2016 to June 2026. Controlled trials in adults comparing PGx-guided prescribing with standard care were eligible. Outcomes included symptom change, response, remission, tolerability, adverse effects, medication–gene congruence, and treatment persistence. Results: Seven controlled studies were included: six focused primarily on MDD and one evaluated antipsychotic persistence in schizophrenia. In MDD, some trials reported higher response or remission rates with PGx guidance, while other clinical outcomes—including symptom change, sustained response, and remission at later follow-up—were not consistently significant. PGx guidance more consistently improved medication selection and reduced predicted gene–drug interactions. In the schizophrenia trial, CYP2D6/CYP2C19 testing did not significantly improve antipsychotic persistence compared with control care. Anxiety outcomes were reported as a subgroup in one trial; no eligible bipolar-disorder trial was identified. Discuss: The findings suggest that improvements in medication selection do not necessarily translate into consistent clinical benefits across outcomes, time points, or psychiatric diagnoses. Evidence is concentrated in MDD, with limited evidence for schizophrenia and no included bipolar-disorder trial. Conclusion: Controlled-trial evidence suggests that PGx-guided prescribing can improve medication selection and may improve selected short-term outcomes in MDD, but clinical benefits are not uniform across outcomes or time points. Evidence is insufficient to support broad conclusions across psychiatric diagnoses, and findings should not be generalized to all commercial multigene panels or all psychotropic medications.