Unrelenting Grief May Be Sign of Distinct Syndrome

"At first, we found this very strange," O'Connor said. "It seemed like it would be a good thing to experience a reward. So why would you find this in a group that is not doing well?"

One of the hallmarks of complicated grief, however, is a persistent sense of longing for the lost one and a tendency to conjure up reveries of that person.

"It's an intense feeling of wanting that person back," Van Wagner said, noting it was sometimes so overwhelming that music became unbearable because it reminded her too much of her mother. "It's an extreme yearning."

Because the nucleus accumbens is involved in anticipating a reward, this might explain why people suffering complex grief are unable to move on, O'Connor and others suspect.

"This is the part of the brain involved in knowing that you want something," she said. "When people who are not adjusting well are having these sorts of thoughts about the person, they are experiencing this reward pathway being activated. They really are craving in a way that perhaps is not allowing them or helping them adapt to the new reality."

The same brain system is involved in other powerful cravings, such those that afflict drug addicts and alcoholics.

"One reason they are stuck is they are getting something pleasurable about thinking about and immersing themselves in memories of the deceased," said Holly Prigerson, an associate professor of psychiatry at Harvard Medical School. "It's like they're addicted to the happy memories."

The findings could help explain why drugs used to treat depression are generally ineffective for complicated grief: They affect a different brain system involving the neurotransmitter serotonin. Drugs that affect the dopamine, a different chemical messenger that is involved with the nucleus accumbens, might be more effective.

In addition, the findings could provide insights that could lead to improved psychotherapy for complicated grief, which has proven highly resistant to therapies used for depression.

"It's almost as though the emotional part of their brains still thinks the person is around," Shear said. "The thinking part of the brain knows they have died. But that information hasn't gotten integrated into the emotional part of the brain."

Shear has had better success treating such patients by focusing on the details of the death, which she thinks helps the brain make that connection.

"You have to help the person's thinking brain communicate better with their emotional brain," Shear said. "This really tells us it's important that we address the reality of the loss so the person can stop craving."

Van Wagner, who has begun to feel better in recent months, said she hoped the findings will lead to better treatments and greater appreciation that not everyone grieves the same way.

"You feel outside pressure that you should be over it by now and move on," she said. "Knowing there's a reason for it, that there is something concrete going on, so to speak, somehow helps."