Pharmacogenetic Testing in Patients With Depression: A Quality Improvement Project

First-line treatment for major depressive disorders (MDDs) is often antidepressants. These medications are commonly trialed and discontinued due to side effects. Pharmacogenetic testing (PGx) allows psychiatric-mental health nurse practitioners to assess patient drug metabolism with the goal of reducing medication trials.

The purpose of this quality improvement project was to examine the impact of PGx on remission rates and clinical outcomes for MDD compared with the standard of care (SOC) in psychiatry.

Outcomes were measured using a problem status system within the site's electronic health record based on patient self-reports and clinician interpretation. No validated scale was used which represents a methodological limitation to the study.

The SOC group had higher remission rates of MDD (38%) compared with PGx (9.8%). The PGx group had a higher occurrence of moderate (24.4%) and severe (17.1%) diagnosis of MDD compared with the SOC group (16% and 8%), respectively. The SOC group had a stable problem status (70%) compared with the PGx group (43.9%). The improving status of PGx was 12.2% compared with SOC at 8%, and the worsening problem status of standard care was 10% compared with PGx at 4.9%. Age did not significantly differ by problem status in the PGx group, F_{(3, 37)} = 0.592, p = .624.

PGx may offer clinical value for patients with severe depression. Results should be interpreted cautiously, and further studies using validated scales and controlled designs are needed.