What is depression?

When doctors talk about depression, they mean the medical illness called major depression. Someone who has major depression has symptoms like those listed in the box below nearly every day, all day, for 2 weeks or longer. There is also a minor form of depression that causes less severe symptoms. Both have the same causes and treatment.

If you're depressed, you may also have headaches, other aches and pains, digestive problems and problems with sex. An older person who has depression may feel confused or have trouble understanding simple requests.