Sounds fairly obvious, but what are the implications? Basically the implications are that events in your life really don't affect your happiness level unless they affect that chemical composition.
So instead of. "I feel bad because X was mean to me"
It is really "I feel bad because my brain is chemically imbalanced and that"s a convenient reason"
This is one thing I tell my spouse a lot because in my opinion she gets depressed from a lack of sunlight and feels better after I open up a window or two.