Many cases of depression are caused by a combination of inherited factors and the brain’s chemical responses to life situations. Relatives of people with depression have a 20 to 25 percent risk of having the disease themselves. But even if depression runs in your family, that doesn’t mean you’ll suffer from this illness. Because you have depression, it doesn’t mean your children will necessarily become depressed. In studies of identical twins who have exactly the same genetic makeup, 30 percent of twins did not develop the mood disorder of the other twin.
Depressive thinking (focusing on negative thoughts) and life stresses (loss of a loved one, unemployment, alcohol abuse, and other medical illness) can trigger a depressive episode. Some medicines, such as drugs for high blood pressure, heart disease, stomach and intestinal problems, sleeping pills, painkillers, sedatives, oral contraceptives, chemotherapy drugs, and antibiotics, can cause depression in some people. For many, depression just seems to “happen” without any particular cause.
Signs to Look ForThe definition of depression is an episode of profoundly bad feelings that are prominent in a person’s life and persist, on a daily basis, for at least two weeks. The episodes may also include some of the following: