Most people who lose someone they love will grieve deeply and then, with time and support, gradually find their way back to life. The grief does not disappear — it changes shape, becomes less acute, makes room for joy alongside sadness. This is adaptation, and it is what most mourners experience.
But for some — researchers estimate between 7 and 15 percent of bereaved people — grief does not follow this course. The acute pain does not diminish. The world does not regain its color. Thoughts of the deceased are not gentle or bittersweet but intrusive and destabilizing. Sleep is disrupted. Functioning deteriorates. What should have been a wound that slowly healed has instead become a chronic condition.
This is complicated grief, now classified in the DSM-5-TR as prolonged grief disorder — and research is beginning to map both its neurobiology and its treatment.
The Stuck Loop
Neuroimaging studies comparing bereaved individuals with and without complicated grief have found distinct patterns of brain activity. Where uncomplicated grief tends to show a gradual diminishment of hyperactivation in reward and attachment circuits over time, prolonged grief disorder is associated with sustained activation of these regions — the brain continuing to signal for the absent person with undiminished urgency.
Researcher Naomi Simon at NYU has described this as a "yearning loop" — a chronic state of longing that has not been able to update to the reality of the loss. The mind knows the person is gone; the attachment system has not yet been able to integrate that knowledge.
Risk factors for complicated grief include the nature of the relationship (closer, more central relationships confer greater risk), the circumstances of the death (sudden or violent loss is higher risk), prior attachment difficulties, concurrent stressors, and the absence of social support.
What Treatment Now Offers
Until recently, prolonged grief disorder was treated primarily with standard therapies for depression and anxiety — which were only modestly effective. The past decade has seen the development of grief-specific treatments with substantially better outcomes.
Complicated Grief Treatment (CGT), developed by Katherine Shear at Columbia, is a structured therapy combining elements of cognitive behavioral therapy with grief-specific techniques including imaginal conversations with the deceased and revisiting the story of the death. In randomized controlled trials, CGT has produced response rates significantly higher than standard interpersonal therapy — with about 70 percent of participants showing meaningful improvement.
A 2023 study published in JAMA found that psilocybin-assisted therapy showed early promise for prolonged grief disorder, with participants reporting profound shifts in their relationship to loss and to the possibility of continued living. The research is at an early stage, but the direction is meaningful.
Grief and the Body
Clinical and research practice increasingly recognizes that complicated grief, like trauma, is held not only in the mind but in the body. Somatic symptoms — chronic pain, fatigue, immune dysregulation — are common in prolonged grief. Body-based interventions, including yoga, trauma-informed movement, and massage therapy, are being studied as adjuncts to psychological treatment.
The body's grief, like the mind's, is not a failure of will. It is evidence of how profoundly love inscribes itself into us — and how deeply its loss is felt. Finding ways to honor that inscription while gradually, gently loosening its grip is the quiet work of grief's long middle.
