What is depression?

Everyone feels sad or low sometimes, but these feelings usually pass with a little time. Depression—also called “clinical depression” or a “depressive disorder”—is a mood disorder that causes distressing symptoms that affect how you feel, think, and handle daily activities, such as sleeping, eating, or working. To be diagnosed with depression, symptoms must be present most of the day, nearly every day for at least 2 weeks.

What are the different types of depression?

Two of the most common forms of depression are:

• Major depression—having symptoms of depression most of the day, nearly every day for at least 2 weeks that interfere with your ability to work, sleep, study, eat, and enjoy life. An episode can occur only once in a person’s lifetime, but more often, a person has several episodes.
• Persistent depressive disorder (dysthymia)—having symptoms of depression that last for at least 2 years. A person diagnosed with this form of depression may have episodes of major depression along with periods of less severe symptoms.