Is depression inherited?
For most people, the risk of developing depression is about 5 per cent. But certain people are probably more at risk because of their genes: if one identical twin suffers from depression there is a 60 per cent chance that the other will, too. Since identical twins share identical genes, this shows that while genes have an important influence in depression, other non-genetic (environmental) factors are involved, too. Manic depression follows a similar pattern and may have an even greater genetic component.