Exploring the potential of pharmacogenetic testing in Alabama Veterans diagnosed with major depressive disorder

Major depressive disorder (MDD) is highly prevalent among Veterans, who often experience inadequate response to first-line antidepressants. Pharmacogenetic testing may improve treatment selection by identifying genetic variants that affect drug metabolism. This study evaluated the prevalence of pharmacogenetically actionable variants and drug-gene interactions (DGIs) in Veterans with MDD.

This retrospective chart review included Veterans aged 19-89 years diagnosed with MDD who were prescribed, previously prescribed, or under clinical consideration for future treatment with at least one mental health medication for which actionable pharmacogenetic guidance exists. Medication histories were assessed for DGIs. The primary outcome was the number of medications with at least one actionable DGI.

Among 32 participants (75% male; 59% Black/African American), 88 current or historical pharmacogenetically actionable mental health medications were identified (median 2 per participant; range 0-9). Thirty-eight (43.2%) medications had ≥1 DGI. Eighteen participants (56.3%) carried ≥1 actionable DGI, with a median of 1 (range: 0-8).

Clinically actionable pharmacogenetic variation was highly prevalent in this Veteran cohort. These findings support the integration of preemptive pharmacogenetic testing into psychiatric care; however, further research is needed to evaluate its impact on treatment response, remission rates, and clinical decision-making.