Everybody feels sad once in a while. Depression, on the other hand, is a complex condition characterized by profound sadness, lethargy, feelings of worthlessness, and a loss of interest in social activities. About 15 million people in the U.S. are diagnosed with clinical depression each year.
Some people don't want to admit they have a problem, and why that's normal
Read why evidence is pointing toward CBT
The research is mixed, but many depression sufferers swear by it