Depression is a medical condition that affects your mood and ability to function. Depression types include clinical depression, bipolar depression, dysthymia, seasonal affective disorder and others. You may have trouble doing normal day-to-day activities, and sometimes you may feel as if life isn't worth living.
More than just a bout of the blues, depression isn't a weakness and you can't simply "snap out" of it. Depression may require long-term treatment. But don't get discouraged. Most people with depression feel better with medication, psychotherapy or both.