I am only beginning to understand depression, although it's been coming and going my whole life. I have just awakened to how depression makes you selfish, even though you are normally a sensitive, compassionate person. It's simply that you are in survival mode. The weird thing about depression is that you usually don't know you have depression until it lifts.
Depression can be a slippery slope or a slow simmer that lasts years. But there are one hundred preventative measures you can do daily to beat it. Number one being learn new habits and challenge the way you can live your life.
Moving, swimming, walking bare foot, eating greens, st johns wort, vitamin B complex, meditation, QiGong, flower essences and warm baths or saunas have been wonderful for me to incorporate everyday- they are medicine.
Since beating depression I've stopped focusing in on myself and have begun to see the world as an engaged learner. I am more resilient and can forbear the challenges of life. My mind is opening up in ways I never expected.
Bottom line for me: depression is what happens when you can't, won't or don't take time out everyday to nurture and look after yourself and to connect to nature and spirit ( this can be as simple as listening to music, doing art or admiring a flower). I believe that when I cut myself off from this source of relaxation and connection I become stressed, and after a while it builds in my body, becoming depression.
Thanks, and all the best :)