Depression comes and depression goes

Depression comes and depression goes 
This is something, I think everyone knows
At times we're happy almost without end
Then someone lies and we crash again
Maybe a friend that we trusted a lot
But to that friend it didn't mean squat
Mostly real friends are true and blue
But some will use you, if only a few
Promises they make and do not keep
Makes disappointment really deep
About all this rudeness what can we do
Be sure one of the rude ones is never you
If you give your word, even if it's mundane
Then keep your promises all the same.
Never use anyone like they were a tool
And always remember the Golden Rule