Love is a kind of intoxication because the deprivation of which is damaging. After a break up, lovers often pass through emotional and physical withdrawal. The intensity of this withdrawal depends, as in any dependence, on the level of addiction versus the level of tolerance… and the theory of DABDA stands true. DABDA is the recovery process from the Love addiction.
P.S. DABDA is the theory of the 5 stages* for coping with death. It does more generally apply to coping with loss.
* D - Denial, A - Anger, B - Bargaining, D - Depression, A - Acceptance