Freud thought when our super-egos abuse our ids, we feel depressed.
If libido is from id, then I think love is from super-ego. Love is
the counterpart of libido. They are like force and counterforce in
physics. Actually many things in psychology include part and
counterpart relations. But I think perhaps in modern scociety the
most common thing is that our super-egos is abused by our ids.For
example, we keep eating when actully we are full.