Johann Hari suffered from depression since he was a teenager. Doctors prescribed medication. It only helped some. He went around the world talking to experts about depression.
In the end, he discovered that certain lifestyles bring on depression -- lack of socializing, being alone, doing what's acceptable in society (he calls junk values), not what your heart desires, and so on. In other words, most depression is not about chemical imbalances, but lifestyle imbalances. Simply put, the person's needs were not being met.
I've created a guided meditation to address these deeper needs that go underground for a variety of reasons. However, when you quiet down and discover them, you can take action to fulfill them -- and your life changes.