The effect of pharmacogenomic testing on response and remission rates in the acute treatment of major depressive disorder: A meta-analysis

Background: Pharmacogenomic testing has recently become scalable and available to guide the treatment of major depressive disorder (MDD). The objective of the current meta-analysis was to determine if guidance from pharmacogenomic testing results in relatively higher rates of remission and response compared to treatment as usual (i.e., 'unguided' trial-and-error method) in adults with MDD.

Methods: Article databases were systematically searched from inception to December 2, 2017 for human studies assessing the clinical utility of pharmacogenomics in the acute treatment of MDD. Treatment outcomes in MDD may be defined continuously or categorically (i.e., response/remission). Herein, we delimit our focus on categorical outcomes. Using a random-effects model, data was pooled to determine the risk ratio (RR) of response and remission, respectively, in the pharmacogenomic-guided treatment group compared to the unguided group.

Results: Four randomized controlled trials (RCTs) and two open-label, controlled cohort studies were included. The pooled RR for treatment response comparing guided versus unguided treatment was 1.36 (95% confidence interval [CI] = 1.14 to 1.62; p = 0.0006; n = 799) in favour of guided treatment. The pooled RR for remission was 1.74 (95%CI = 1.09 to 2.77; p = 0.02, n = 735) also in favour of guided treatment. Heterogeneity in study results suggest that different genetic tests may variably impact response and remission rates.

Limitations: The available evidence is limited, with significant methodological deficiencies.

Conclusion: The current analysis provides preliminary support for improved response and remission rates in MDD when treatment is guided by pharmacogenomics.