People with prolonged grief disorder have increased activity in areas of the brain involved in memory and emotion processing when they see death-related images, like a graveyard
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For most people, the intense sting of grief eases with time. For some, however, persistent and painful grief remains, developing into prolonged grief disorder. A new review of the condition, which affects around 5 per cent of bereaved people, sheds light on how it develops. This could help doctors predict which recently bereaved people will benefit from extra support.
The decision to include prolonged grief disorder (PGD) in the American Psychiatric Association’s diagnostic manual in 2022 sparked intense debate over whether it was pathologising a normal human response to loss and imposing an arbitrary timeline on what constitutes “normal” grief. Now, an analysis of the brain activity of people with and without PGD suggests it is a condition in its own right.
Richard Bryant at the University of New South Wales in Sydney, Australia, compared the brain activity of PGD with that seen in other psychiatric conditions that can follow a bereavement, such as post-traumatic stress disorder (PTSD), depression or anxiety. They found that while there are overlaps, people with PGD repeatedly show more pronounced changes in a larger number of reward-related brain circuits.
Several studies, for instance, have found that people with PGD show significantly greater activation of the nucleus accumbens, which processes reward and motivation, in response to grief-related words and images than people who are bereaved but don’t have PGD. The strength of this activation also correlated with self-reported yearning for those lost.
Compared with those with PTSD or anxiety, people with PGD also show a bias towards reminders of the deceased. By contrast, those with PTSD or anxiety tend to show neural activity that promotes avoidance behaviours.
Other studies show heightened activation of the amygdala and right hippocampus – regions involved in emotion processing and memory – when people with PGD view death-related images, such as a graveyard, compared with those experiencing typical grief. By contrast, these same regions show greater deactivation in response to positive images, such as serene landscapes. This suggests disrupted emotional regulation alongside a diminished capacity to experience positive emotion.
In PGD, the brain’s reward system “locks” onto the deceased and fails to find reward elsewhere, says Bryant, producing an intense longing for the lost loved one. “The key distinction between PGD and normal grief is the time frame – that is, the person is ‘stuck’ in their grief such that they do not adapt in the way that most people do,” says Bryant.
Despite the review being comprehensive, there is no straightforward way that the information can be helpful in diagnosing PGD, says Katherine Shear at Columbia University in New York. This is, in part, because most grieving people will never be offered brain scanning, but also because grief is so complex and variable that it is hard to examine with a one-off scan.
Shear says neuroimaging is just starting to incorporate some of this complexity by doing “two-person neuroscience”, which focuses on brain activity during live interactions, helping us understand how grief is shaped by social context, cultural expectations and levels of support.
Where the review may be useful is in helping to predict who might go on to experience PGD after a bereavement. In one study, bereaved adults had their brain scanned within a year of their loss and at various times over the next six months. Greater connectivity between the amygdala and regions involved in planning, inhibiting behaviours and filtering important information in that initial scan predicted worsening grief symptoms over time, suggesting that such patterns – and the behaviours associated with them – might forecast a person’s risk of PGD.
Although we know that there are several psychosocial factors that differentiate individuals who are more likely to have PGD, we cannot reliably identify who is heading toward this, says Joseph Goveas at the Medical College of Wisconsin. “Early detection would allow for timely interventions, which could range from supportive approaches such as grief groups to more specialised care.”
Evidence for specific neurobiological mechanisms also strengthens the case for recognising PGD as something distinct from other grief-related conditions, while pointing to ways that doctors can tailor treatment.
“Understanding both overlapping and distinct neurobiological mechanisms may help reduce misdiagnosis and inappropriate treatment,” says Goveas. “For example, while PGD typically does not respond to antidepressants, it does respond to grief‑specific psychotherapies. Conversely, when PGD co-occurs with major depression, combining antidepressants with PGD‑targeted therapy can effectively treat depressive symptoms.”
Need a listening ear? UK Samaritans: 116123; US 988 Suicide & Crisis Lifeline: 988; hotlines in other countries.
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