Mourning the death of a loved one is about as universal a human emotion as exists, and it's not even confined to humans; there's evidence of it in other primates and even elephants. From its beginnings, psychotherapy has recognized the special challenge of grief and its relationship to depression (or, as Freud put it in the title of one of his best-known essays, "Mourning and Melancholia").

The dead never quite leave us; they return in dreams and reveries, they inhabit the pictures on our walls and lurk in our cell phones and disk drives. Some people find dreams comforting, while for others there is nothing as sad as the moment when the vision of a dead parent, spouse or child slips away with the dawn, and they awaken reluctantly to a day their loved ones will never see. But as researchers have turned their scanners on the dark realms of the psyche that grief inhabits, they are discovering the unsettling power of waking reveries. How one relates to them can make a large difference in how one recovers from the death of a loved one.

This insight comes from studying what therapists call "complicated grief," which basically means grief that doesn't go away. "It has to persist for six months or more in a way that interferes with your daily functioning," says UCLA researcher Mary-Frances O'Connor. "Every day you're experiencing yearning for the deceased, looking for them in a crowd, or expecting them to come home."

In a paper in the journal Neuroimage, O'Connor and her colleagues describe using an fMRI machine to probe the neurological basis for complicated grief among a small sample of women who had lost a close relative to breast cancer. Ordinary grief is apparent on a brain scan: show a bereaved daughter a picture of her mother, and areas of the brain that process emotional pain are activated. The women with complicated grief showed that pattern, but something else as well: activity in the nucleus accumbens, a brain region associated with pleasure, rewards and addiction. "When the women came out of the scanner, the complicated-grief group rated themselves as feeling more negative than the others," O'Connor said. "But they also said things like, 'Oh, it was so nice to see my mom again.' These are the ones who pore over picture albums, talk about the person all the time, almost as if she was still here." The women in that situation were unconsciously prolonging their grief, she concluded, because memories of the person they missed gave them pleasure—as well as pain.

Janice Van Wagner, a 34-year-old Los Angeles woman, was one of those: she lost her mother two years ago to breast cancer, at the relatively young age of 58. Losing a mother or sister to breast cancer is especially difficult for many women because it implies the survivor herself might be at risk for the disease. Van Wagner's mother, as is often the case with breast cancer, suffered greatly in the last weeks of her life. And as an only child, unmarried and childless herself, Van Wagner had an especially close relationship with her mother. "The grief matched the intensity of the relationship," she said, comparing her yearning to the craving an addict might feel for a drug. "I couldn't stand the pain. Nothing felt pleasurable to me. I couldn't even listen to music."

Van Wagner's life is closer to normal now, but researchers estimate the prevalence of "complicated grief" at 10 to 20 percent among the bereaved, and the condition is being considered for inclusion in DSM-V, the next edition of the standard textbook of mental illness. This will raise awareness and promote research, but the price will be to pathologize a state that goes back to the very roots of the human condition. I've never seen a nucleus accumbens but I know about grief, and I can't help but wonder: maybe the women with complicated grief just loved their mothers more.

© 2008