Really liking lots of these replies and 'strategies' !

And I agree that it's generally preferable to confront, work through etc sources of inner problems; however, when there's nothing you're actually depressed about, not even a case of mental/emotional exhaustion, just plain dirty depressed ...well there's no benefit there in delving into it, except to feel even worse about how you're feeling and therefore worse about yourself. I then find it best to think and analyse as little as possible, for the sake of my sanity and teeny tiny shred of well-being I can huddle into.