Sadness is one of the basic human emotions experienced by everyone at some point in their life. Most people feel sad as a normal reaction to loss, rejection, disappointment, or other difficult situations. While it is normal to feel sadness, the feeling usually subsides on its own in time. Depression, on the other hand, is more than just feeling sad. Depression is a mood disorder that can show up without notice or explanation and usually lasts at least two weeks or longer. Unlike sadness, depression can cause you to lose interest in activities you once enjoyed. For example, if you once loved cooking or playing sports, depression can make those activities seem unappealing and unenjoyable for no apparent reason. It can make you feel angry, irritable, distracted, and/or insecure. (An estimated 3.2 million adolescents aged 12 to 17 in the United States had at least one major depressive episode. This number represented 13.3% of the U.S. population aged 12 to 17. An estimated 17.3 million adults in the United States had at least one major depressive episode. This number represented 7.1% of all U.S. adults.) If you are feeling sad or depressed, start by talking to someone who can help like a good friend, your school guidance counselor, or trusted mentor.