What really causes depression and anxiety--and are we treating them correctly?

Award-winning journalist Johann Hari struggled with depression since childhood. He was told that his problems were caused by a chemical imbalance. He started treating it with antidepressants as a teenager.

As an adult he's tried to find out whether this was true--and as you'll hear in our conversation with him...he learned that almost everything we have been told about depression and anxiety is wrong.