Well if you want to get to the root of all feelings they are:
Love and Fear
Depression branches off of the fear tree.

For me depression only happens when I am tired of feeling a certain way over and over again.

Change up your habits. Smoke some chronic, try something NEW!

I am also finding I have to change my habits more and more because I am finding myself bored if I do not. Then I start sleeping more because I have nothing to do and after 2 weeks you could find yourself in a dark place.