Overview

Most people feel sad or irritable from time to time. They may say they're in a bad mood. A mood disorder is different. It affects a person's everyday emotional state. Nearly one in ten people aged 18 and older have mood disorders. These include depression and bipolar disorder (also called manic depression).

What is Depression in teens?

Teen depression is a serious medical illness. It's more than just a feeling of being sad or "blue" for a few days. It is an intense feeling of sadness, hopelessness, and anger or frustration that lasts much longer. These feelings make it hard for you to function normally and do your usual activities. You may also have trouble focusing and have no motivation or energy. Depression can make you feel like it is hard to enjoy life or even get through the day.

What is Bipolar?

Bipolar disorder is a serious mental illness. People who have it go through unusual mood changes. They go from very happy, "up," and active to very sad and hopeless, "down," and inactive, and then back again. They often have normal moods in between. The up feeling is called mania. The down feeling is depression. 

https://medlineplus.gov/mooddisorders.html