Translational psychiatry: Bringing pharmacogenomic testing into clinical practice

Significant inter-individual variability exists in antidepressant response, therapeutic dosage, and adverse effect profile. Prolonged times to response or remission represent a period of suffering associated with increased risk for morbidity and mortality. Improving care in depression treatment using a more biologically informed selection of psychopharmacologic agents through genotyping has become a reality in psychiatric practice. Routine genotyping has now become available for gene variations that code for proteins involved in neurotransmission and for drug-metabolizing enzymes involved with the disposition of many pharmacologic agents including antidepressants. Clinical validation and reliability of genotyping, access to testing, uniformity and clarity in test interpretation, and clinician and patient education are critical to this process of innovation diffusion. This article focuses on the introduction of pharmacogenetic testing to the daily practice of psychiatry. Challenges inherent in innovation diffusion in general and in the application of pharmacogenetic testing in particular are addressed. Study data involving the introduction and integration of pharmacogenomic testing into two different types of community psychiatric practice are presented. The article concludes with a discussion of the ethical issues raised in this process and its impact on the physician-patient relationship.