For a study, researchers sought to ascertain if choosing an antidepressant drug was influenced by pharmacogenomic testing and whether such testing improves clinical results.

A practical, randomized clinical study that compared pharmacogenomic testing-guided therapy with standard care. Participants comprised 1,944 patients and 676 medical professionals. From July 2017 to February 2021, participants were enrolled from 22 Department of Veterans Affairs medical facilities, with follow-up finishing in November 2021. Patients with major depressive disorder (MDD) starting or changing therapy with a single antidepressant were eligible. A current drug use problem, mania, psychosis, or concomitant pharmaceutical therapy were all exclusion factors. Clinicians in the pharmacogenomic-guided group (n=966) were given the findings of a commercial pharmacogenomic test. After 24 weeks (n=978), the comparison group got standard therapy and had access to pharmacogenomic findings. The proportion of prescriptions filled in the 30 days following randomization with a predicted drug-gene interaction and the disappearance of depression symptoms as determined by the Patient Health Questionnaire-9 (PHQ-9) (remission was defined as PHQ-9 ≤ 5) was the co-primary outcome. Remission was evaluated by blinded raters during a 24-week period as a repeated measure.

In the 1,944 patients who were randomly assigned (mean age, 48 years; 25% female), 1,541 (or 79%) finished the 24-week examination. The predicted risks for taking an antidepressant with no, mild, or significant drug-gene interactions were 59.3%, 30.0%, and 10.7%, respectively, in the pharmacogenomic-guided group, as opposed to 25.7%, 54.6%, and 19.7% in the standard treatment group. When comparing no drug-gene interaction vs. moderate/substantial interaction and no/moderate vs. substantial interaction, the pharmacogenomic-guided group was more likely to be prescribed a drug with a lower potential drug-gene interaction (odds ratio [OR], 4.32 [95% CI, 3.47 to 5.39]; P<.001) and substantial interaction (OR, 2.08 [95% CI, 1.52 to 2.84; P=.005) (P<.001 for overall comparison). Remission rates were higher for patients whose care was guided by pharmacogenomic testing than for patients receiving usual care over a 24-week period (OR, 1.28 [95% CI, 1.05 to 1.57]; P=.02; risk difference, 2.8% [95% CI, 0.6% to 5.1%]), but they were not statistically different at week 24 when 130 patients in the pharmacogenomic-guided group and 126 patients receiving usual care were in remission (estimated risk difference, 1.5% [95% CI, −2.4% to 5.3%]; P=.45).