A new review published in Trends in Neurosciences reveals that prolonged grief disorder may persist due to changes in brain circuits linked to reward, attachment, and emotional processing, helping explain why some people struggle to recover after losing a loved one.
By Ayo Tom,
Grief is often described as a journey with peaks and valleys, but for some people, it does not ease with time. While most bereaved individuals gradually adjust to life after loss, an estimated 10 percent develop a condition known as prolonged grief disorder (PGD), where intense sorrow, guilt, and longing continue for more than six months and significantly disrupt daily life.
Formally classified as a psychiatric disorder by the World Health Organisation in 2018, PGD is marked by persistent bereavement-related distress. According to the NHS, those affected may spend much of their time thinking about the person who has died, struggle to accept the loss, feel that life has lost meaning, or experience difficulty returning to normal routines. Some may even have suicidal thoughts. Although traumatic or sudden deaths increase the risk, not everyone exposed to such losses develops the disorder — a puzzle that has challenged scientists.
A new review published in the medical journal Trends in Neurosciences sheds light on why grief lingers for some individuals. Researchers from the University of New South Wales examined existing studies on the neurobiology of PGD, focusing largely on functional MRI (fMRI) scans that track changes in brain activity when bereaved individuals look at photos of the deceased or recall memories of their loss.
The findings suggest that PGD shares certain brain activity patterns seen in depression and anxiety disorders. However, what distinguishes prolonged grief is notable activity in regions associated with reward and attachment. These include the nucleus accumbens and orbitofrontal cortex — areas involved in desire and motivation — as well as the amygdala and insula, which help process emotional responses.
Lead author Professor Richard Bryant described PGD as “the new kid on the block in terms of psychiatric diagnoses,” emphasizing that it is not a fundamentally different kind of grief, but rather a state in which a person becomes “stuck.” He explained that grief often involves a deep longing or craving for the deceased, and in PGD, this yearning may become neurologically reinforced.
In simple terms, the brain’s reward system — which typically motivates us toward pleasurable or meaningful experiences — may continue to activate in response to reminders of the lost loved one. Instead of gradually recalibrating, the system sustains the emotional attachment, making it harder for the individual to adapt to the absence. This overlap with reward circuitry may explain why some people experience an almost addictive pull toward memories of the deceased, intensifying rumination and emotional pain.
Researchers also observed similarities between PGD and post-traumatic stress disorder, particularly in patterns linked to emotional distress and repetitive negative thinking. Bryant noted that such overlap is not surprising, given the shared psychological features.
Because PGD is a relatively recent diagnosis, available data remains limited, and most studies involve small sample sizes. Bryant hopes future research will follow larger groups of bereaved individuals over time to better understand how brain activity evolves as people either recover or remain stuck in grief.
Importantly, experts stress that prolonged grief disorder is treatable. But awareness is crucial. “To actually deal with prolonged grief, we need to recognise it as a disorder,” Bryant said. Identifying those at risk could help ensure that individuals receive targeted psychological interventions rather than silently enduring years of unresolved sorrow.
The emerging science underscores a powerful message: while grief is universal, recovery is not always automatic — and for some, the brain itself may be holding on.