This disorder affects your mood and your energy levels. It's also known as "manic depression." With it, you have periods, called "manic episodes," during which you feel happy and full of energy. You also have "depressive episodes." During these times you feel sad, hopeless and tired. You can even have episodes that are a mix of these intense feelings. These extreme mood swings can disrupt your life.

Everyone feels sad sometimes. But if deep sadness and hopelessness makes your daily life hard, you may be depressed. Depression can last for a long time. You may have depression many times throughout your life.

This is a form of long-term depression. We also call it "chronic depression." It can make you feel sad or irritable on most days, and this mood can last for years. With this form of depression, your feelings are milder than they are in someone who has major depression.

This type of depression develops in some mothers after childbirth. This makes it hard for you to care for your baby. And it can severely impact your life.

This is a type of depression that is linked to the seasons. For most people with SAD, depression comes in fall and winter and goes away in spring and summer. But others have depression during the summer months.