Sooner or later most of us suffer deep grief over the death of someone we love. The experience often causes people to question their sanity—as when they momentarily think they have caught sight of their loved one on a crowded street. Many mourners ponder, even if only abstractedly, their reason for living. But when are these disturbing thoughts and emotions normal—that is to say, they become less consuming and intense with the passage of time—and when do they cross the line to pathology, requiring ongoing treatment with powerful antidepressants or psychotherapy, or both?

Two proposed changes in the “bible” of psychiatric disorders—­the Diagnostic and Statistical Manual of Mental Disorders (DSM)—­aim to answer that question when the book’s fifth edition comes out in 2013. One change expected to appear in the DSM-5 reflects a growing consensus in the mental health field; the other has provoked great controversy.

In the less controversial change, the manual would add a new category: Complicated Grief Disorder, also known as traumatic or prolonged grief. The new diagnosis refers to a situation in which many of grief’s common symptoms—such as powerful pining for the deceased, great difficulty moving on, a sense that life is meaningless, and bitterness or anger about the loss—­last longer than six months. The controversial change focuses on the other end of the time spectrum: it allows medical treatment for depression in the first few weeks after a death. Currently the DSM specifically bars a bereaved person from being diagnosed with full-blown depression until at least two months have elapsed from the start of mourning.

Those changes matter to patients and mental health professionals because the manual’s definitions of mental illness determine how people are treated and, in many cases, whether the therapy is paid for by insurance. The logic behind the proposed revisions, therefore, merits a further look.

Abnormal Grief

The concept of pathological mourning has been around since Sigmund Freud, but it began receiving formal attention more recently. In several studies of widows with severe, long-lasting grief in the 1980s and 1990s, researchers noticed that antidepressant medications relieved such depressive feelings as sadness and worthlessness but did nothing for other aspects of grief, such as pining and intrusive thoughts about the deceased. The finding suggested that complicated grief and depression arise from different circuits in the brain, but the work was not far enough along to make it into the current, fourth edition of the DSM, published in 1994. In the 886-page book, bereavement is relegated to just one paragraph and is described as a symptom that “may be a focus of clinical attention.” Complicated grief is not mentioned.

Over the next few years other studies revealed that persistent, consuming grief may, in and of itself, increase the risk of other illnesses, such as heart problems, high blood pressure and cancer. Holly G. Prigerson, one of the pioneers of grief research, organized a meeting of loss experts in Pittsburgh in 1997 to hash out preliminary criteria for what she and her colleagues saw as an emerging condition, which they termed traumatic grief. Their view of its defining features: an intense daily yearning and preoccupation with the deceased. In essence, it is the inability to adjust to life without that person, notes Mardi J. Horowitz, professor of psychiatry at the University of California, San Francisco, and another early researcher of the condition. Prigerson, then an assistant professor at the Western Psychiatric Institute and Clinic in Pittsburgh, hoped the meeting would begin the process of finding enough evidence to support changing the DSM. “We knew that grief predicted a lot of bad outcomes—over and above depression and anxiety—and thought it was worthy of clinical attention in its own right,” says Prigerson, now a professor of psychiatry at Harvard Medical School.

A spate of studies since then—not only of widows but of parents who had lost a child, tsunami survivors and others—has further confirmed and refined that initial description. In 2008 researchers got their first hint of what complicated grief disorder looks like at the neurological level. Mary-Frances O’Connor of U.C.L.A. scanned the brains of women who had lost their mother or a sister to cancer within the past five years. She compared the results of women who had displayed typical grief with those suffering from prolonged, unabated mourning. When, while inside the scanner, the study participants looked at images of the deceased or words associated with the death, both groups showed a burst of activity in neurological circuits known to be involved in pain. The women with prolonged grief, however, also showed a unique neural signature: increased activity in a nub of tissue called the nucleus accumbens. This area, part of the brain’s reward center, also lights up on imaging scans when addicts look at photographs of drug paraphernalia and when mothers see pictures of their newborn infant. That does not mean that the women were addicted to their feelings of grief but rather that they still felt actively attached to the deceased. Meanwhile clinical studies have shown that a combination of cognitive therapy approaches used to treat major depression and post-traumatic stress may help some people with complicated grief work through it.

As these and other studies began to pile up, a few researchers turned to complex statistical analysis to validate more precisely the exact combination of features that define the condition. In 2009, more than 10 years after the Pittsburgh panel, Prigerson published data collected from nearly 300 grievers she had followed for more than two years. By analyzing which of some two dozen psychological symptoms tend to cluster together in these participants, she devised the criteria for complicated grief: the mandatory presence of daily yearning plus five out of nine other symptoms for longer than six months after a death [see box at right]. This is exactly the type of rigorous, quantitative study that is needed before a condition makes it into the DSM. “People who meet the criteria for complicated grief do not necessarily meet criteria for either depression or post-traumatic stress disorder,” says Katherine Shear, a professor of psychiatry at Columbia University. “If you didn’t have this disorder [in the DSM], then those people would not get treatment at all.”

Controversial Treatment

The case for diagnosing people as depressed and treating them accordingly when they are still newly bereaved is more contentious. Although some symptoms of grief and depression overlap (sadness, insomnia), the two conditions are thought to be distinct. Grief is tied to a particular event, for example, whereas the origins of a bout of clinical depression are often more obscure. Antidepressants do not ease the longing for the deceased that grievers feel. So in most cases, treating grieving people for depression is ineffective.

A few studies, however, have suggested that mourning may trigger depression in the same way that other major stresses—such as being raped or losing one’s job—can bring about the condition. If so, some people who grieve may also be clinically depressed. It seems unfair, advocates of changing the DSM argue, to make mourners wait so long for medical help when anyone else can be treated for depression after just two weeks of consistent depression. “On the basis of scientific evidence, they’re just like anybody else with depression,” says Kenneth S. Kendler, a member of the DSM-5 Mood Disorder Work Group, which reviews all proposed changes to the manual related to anxiety, depression and bipolar disorder (a condition characterized by extreme mood swings). It is for this reason that the group recently suggested deleting the clause that specifies a two-month wait before mourners can receive a diagnosis of, and therefore treatment for, depression.

Critics of the move counter that it will lead to unwarranted diagnoses and overtreatment. “It’s a disastrous and foolish idea,” says Allen Frances, who chaired the task force that produced the fourth edition of the DSM. He worries about how the DSM-5 may be used by sales representatives from pharmaceutical companies to urge doctors to write more prescriptions. Indeed, Frances believes that changes in the edition that he oversaw inadvertently sparked an unwarranted explosion of diagnoses for bipolar disorder in children. Prigerson, for her part, predicts a general backlash against the idea that mourners might ever need psychiatric treatment. “There will be vitriolic debates when the public fully appreciates the fact that the DSM is pathologizing the death of a loved one within two weeks,” she says.

In many ways, parsing the differences between normal grief, complicated grief and depression reflects the fundamental dilemma of psychiatry: mental disorders are diagnosed using subjective criteria and are usually an extension of a normal state. So any definition of where normal ends and abnormal begins will be the object of strongly held opinions. As Frances says, “There is no bright line—it is always going to be a matter of judgment.”