Depression is the leading cause of disability in the world; in the United States, close to ten percent of adults struggle with the disease. But because it’s a mental illness, it can be a lot harder to understand than, say, high cholesterol. Helen M. Farrell examines the symptoms and treatments of depression, and gives some tips for how you might help a friend who is suffering.
![Depression](https://www.wienercouch.at/drei/wp-content/uploads/2017/10/depression2-770x433.jpg)