Personalized medicine aims to integrate a number of characteristics such as genetic and epigenetic variations, other biomarkers, clinical symptoms, and environmental factors in order to predict susceptibility to disease, aid in diagnosis, and identify efficacious treatments with maximum likelihood of favorable response and minimal chance of adverse effects. The use of personalized medicine approaches in psychiatry is underdeveloped, but has a profound potential for improving prevention and treatment. There are a number of studies that have found promising associations between a variety of biomarkers and clinical response to psychopharmacological treatment in various psychiatric disorders. These biomarkers include neuroimaging, electrophysiology, peripheral serum, and plasma biomarkers, and variations in genomics, epigenetics, proteomics, and metabolomics. Ultimately, the best model for precision medicine in complex, multifactorial diseases such as psychiatric illnesses will likely involve integrated methodology that combines information from multiple sources including biologic, clinical, and environmental data. While much progress has been made in the development of valid biomarkers in psychiatric disorders, there is much work to be done in determining their clinical utility.