is depression inherited?
The evidence is overwhelming that major depression has a strong genetic component. In one study, the biggest predictor of the development of depression in adopted-away women was the presence of depression in their biological mothers whom they had never met. The presence of depression in the adoptive family or of major life stressors was not as great a predictor of the development of depression as family history. 50% of identical twins will develop depression if the other twin developed depression; this rate is 25% for fraternal twins. A family history of depression makes you 2-5 times more likely to develop depression yourself.