Genetic Risk Factors of Depression

Research on the genetic underpinnings of depression has rapidly advanced in the past decade. This field of research provides a promising avenue toward improving the diagnosis of, prevention of, and treatment for this devastating disorder. The goal of this chapter is to review the main genetic and gene-by-environment interaction findings on depression. We first describe family and twin studies used to empirically study the familial aggregation of depression. Second, we provide a review of the genome-wide association studies (GWAS) published to date. Building on GWAS findings, we will discuss the use of polygenic risk scores in predicting depression. We also review the most robust candidate gene studies and gene-by-environment interaction studies. Finally, we discuss the clinical implications of the findings and promising strategies for making further progress within this field.