The teenage years can be challenging, and it’s normal for young people to feel sad sometimes. But when those feelings don’t go away, the problem may be depression. This illness affects mood, thoughts, and behavior and can cause difficulties with eating, sleep, and schoolwork. Depression can have many causes–family problems, bullying, or even the stresses of everyday life. Learn the symptoms of depression and find out how to get help. Depression is treatable, and most people who get treatment feel better and enjoy life again.