2. Your genes play a role.
Experts believe that about 50% of depression stems from genetics. This probably doesn"t come from just one gene but a combination. But, if you have a parent or sibling with depression, your risk is two to three times greater than it is for someone without this family history. The more severe the depression, the more likely the link to genetics. Other causes include child abuse, loss of a parent early in life, and severe stress. However, often the cause is not known.