Depression and Heredity: Is Depression Genetic?

Over a thousand studies have been conducted on the genetic basis and heredity of depression, major depressive disorder, and other depressive disorders. These studies have spanned analyses of candidate genes, genome-wide association studies, genome-wide sequencing, family and twin studies. They’ve evaluated the significance of particular genetic variations that signal increased risk of depression. If you have close relatives and family members who are diagnosed with depression, you or a loved one may have a predisposition to developing psychiatric disorders, particularly in the face of stressful life events.

All have concluded that the contribution of genetic factors to the risk of the onset of Depressive Disorders is quite large.¹ However, they have also found that while major depression is a familial disorder, and its familiality mostly or entirely results from genetic influences; the development of depression also relies on environmental factors specific to an individual.² Because major depression is a complex disorder, it results from a combination of both environmental and genetic influences–these results and findings are not mutually exclusive. A family history of mental health conditions, in combination with external stressor, can contribute to the prevalence of depression.

Most recently, researchers used a meta-analysis to report “a genome-wide significant locus for depression that implicates genes that are highly plausible for involvement in the etiology of recurrent depression.”³ While they did not locate the exact genetic components, or a “depression gene,” the increased data and information helped to point them into a closer direction of which chromosomes are affected specifically in the heritability of depression.