Depression isn't just a chemical imbalance. These imbalance are created as a result of our thoughts/beliefs and the emotions that follow. As we change our thoughts/beliefs and feel our feelings, our brain chemistry changes.
I suffered from severe depression for most of my life. I was never able to find an antidepressant that actually worked for me so I was forced to find alternative methods to heal my depression. I did a lot of therapy, group work, reading, and taking classes and workshops in subjects from psychology to energy work.
The thing that shifted my depression the most was the anger and boundaries work that I did. I discovered that depression is anger turned inward and that most of our anger that we are stuffing is related to our lack of boundaries and/or our boundaries being constantly invaded. Like every good little girl I learned to stuff my feelings, especially anger, and to pretend life was fine. I also learned that these behaviours are what change our brain chemistry and therefore as we change the behaviours by changing the thought patterns behind the behaviours then we change the chemistry.
I used anger journaling to start to express all my unexpressed, deep, hidden anger appropriately. I got 9x12 sketchbooks and poured all my anger and deep sorrow on paper. I call it "puking on paper." I also would sit and tear to bits old phone books and at times scream in the car. I also learned to have all of my emotions. To give them the space and time to pass through me and to no longer stuff them.
Of course, the most vital thing I did was learn what boundaries were, why they are important, and how to have them. I also gained permission for self-care. (A great book is The Art of Extreme Self-Care by Cheryl Richardson) I now understand that giving ourselves away, not saying no when we need to, and never creating time for ourselves is also a great contributor to anger and depression.
I no longer suffer from depression. I now seek help when I am overwhelmed by life, put myself first on the list, continue to gather information about healing, and most of all resource myself to support myself in actually feeling all of my feelings. I also work deeply to question my core belief systems and to become aware of the vicious thoughts that can run through my head. I have learned to be kind to myself and to question that voice in my head rather than buy in to all the "I'm not good enoughs."