What are the genetic and environmental contributors to depression, and how can these influence treatment options?

Depression is a mental illness with the highest prevalence worldwide, and a large percentage of individuals will have depression symptoms at some point in their lives. This paper will examine genetic and environmental contributors to depression and consider how this information can be used to develop more effective treatments. In particular, genetic contributions will be informed by genome-wide association studies that identify gene variants likely to be involved in depression, as well as several pathways by which depression can modulate brain morphology. The paper will also consider the interplay between genetics and environmental stimuli like trauma or social stress, and discuss how genetic variation may contribute to the propensity of an individual to develop depression. Finally, the paper will consider how antidepressant medications can be prescribed on the basis of genetic/environmental information in order to yield an individualized and more effective treatment strategy.