Understanding Prolonged Grief Disorder
A review published in February in the journal Trends in Neurosciences takes a close look at the brain biology behind what researchers call prolonged grief disorder, or PGD—a condition only formally recognized as a psychiatric diagnosis in 2018. The lead author, Richard Bryant, a trauma researcher at the University of New South Wales in Australia, has spent years trying to understand why some people simply cannot move forward after a loss.
“It’s not that it’s a different type of grief,” Bryant explained. “It’s just more that the person is stuck.”
When grief becomes something else
About one in every 20 bereaved people develops PGD. The symptoms will feel familiar to anyone who has experienced deep loss—intense yearning, a sense that life has lost its meaning, difficulty accepting that the person is really gone. What sets PGD apart isn’t the nature of those feelings but their persistence. By definition, the condition involves grief that doesn’t ease after six months. For many sufferers, it goes on far longer.
It’s a distinction worth making carefully. PGD is not the same as depression, though the two can overlap. It isn’t simply grieving too long or failing to be resilient. Something specific appears to be happening in the brain—something that keeps the grieving person locked in a state of longing they cannot escape.
The brain’s reward system, hijacked
To understand what goes wrong, Bryant and his colleagues looked at neuroimaging studies, or brain scans taken while bereaved people were shown reminders of the person they lost. What they found, consistently, was unusual activity in the brain’s reward circuits—specifically, areas associated with desire, craving, and motivation.
In other words, the grieving brain isn’t simply sad, it’s longing in the same way that drives hunger or addiction. The person who is gone becomes, in a very real brain-chemistry sense, something the mind keeps reaching for and cannot find.
“It gelled with this notion that grief is characterized by a craving for the deceased,” Bryant says.
Other parts of the brain involved in processing emotions also show changes in people with PGD, pointing to a system that is stuck in a heightened state of emotional alertness long after it should have begun to quiet down.
Why it matters for treatment
Understanding PGD as a neurological condition, not a personal failing, has real implications for how we treat it. Effective therapies do exist, including forms of cognitive behavioral therapy adapted for prolonged grief. But those treatments can only help people who are first identified and diagnosed—and that’s where the system currently falls short.
Bryant’s goal is raising awareness. Older adults in particular are vulnerable to PGD. The loss of a spouse after decades together, the death of a sibling who shared a lifetime of memories—these are deep losses. And we are learning more and more about the biological processes behind this condition.
The research is still young, with small study sizes and much left to learn. But the direction is encouraging. The more precisely scientists can map what prolonged grief looks like in the brain, the better equipped clinicians will be to recognize it and to help the people living inside it finally find their way through.