An article in the Washington Post, about the physiology of grief, uses brain chemistry to explain why grieving people are unable to move on. The nucleus accumbens, a brain area which governs grieving, is also involved in the process of anticipating a reward.
This is the part of the brain involved in knowing that you want something, so that grievers tend to remain fixated on the missing object or loved one - grief as craving.
The same brain system is involved in other cravings, e.g. for drugs or alcohol.
"The findings could explain why drugs used to treat depression are generally ineffective for complicated grief: [the drugs] affect a different brain system involving the neurotransmitter serotonin. Drugs that affect dopamine, a different chemical messenger that is involved [with grief] might be more effective."
How fortunate I am to be using one of the few bliss pill prescriptions that affects both serotonin and dopamine. Perfect balance wins again.
Incidentally, an old friend in Glasgow passed on his unused stash of bliss pills, a whole month's supply. To those that have shall be given.
PS - bloggers in the grip of cravings might wish to discuss this research with their doctor.