Depression treatment is currently determined by trying one medication, seeing if it works, and when it doesn't or has significant side effects, trying another one. A May 7, 2018 poster (#110) at the American Psychiatric Association meeting described another option for guiding depression medication selection, pharmacogenomic testing. The poster described study results of 1167 outpatients with moderate to very severe treatment-resistant depression for whom at least one antidepressant medication had failed. Patients had their DNA sample taken with a cheek swab which was tested for 12 genes and 56 medications. The GeneSight test combines personal genetic data with medication information to guide treatment decisions. In this study, patients with treatment-resistant depression were 30% more likely to respond to treatment and 50% more likely to achieve remission when their medication selection was guided by the genetic test. Further pharmacogenomic testing studies are needed to confirm this study's results, but it is exciting that testing that offers such clinical benefit is available.