People with PGD are preoccupied by grief and feelings of loss to the point of clinically significant distress and impairment, which can manifest in a variety of symptoms including depression, emotional pain, emotional numbness, loneliness, identity disturbance and difficulty in managing interpersonal relationships.

PGD is estimated to be experienced by about 10 percent of bereaved survivors, although rates vary substantially depending on populations sampled and definitions used.

Spouses, parents, and children of deceased tend to display highest severities, followed by siblings, in-laws, and friends.

[13] Grief is a common response to bereavement, occurring in a variety of severities and durations, however only a minority of cases of grief meet the severity and duration criteria to merit diagnosis of PGD; it is considered when an individual's ability to function and level of distress over the loss is extreme and persistent.

[7][8][6] Although normal grief remains with the bereaved person far into the future, its ability to disrupt the survivor's life is believed to dissipate with time.

PGD can be distinguished from depressive disorders with distress appearing specifically about the bereaved as opposed to a general low mood.

[20][41] A combination of relational and cognitive-behavioral interventions have shown evidence for efficacy when treating individuals who have lost loved ones to suicide.

[13] This includes interventions that target the client's sense of self and lingering emotional attachment to the deceased, as well as any experiences of intrusion, anxiety, and/or avoidance.

[47][48] Based on numerous findings of maladaptive effects of prolonged grief, diagnostic criteria for PGD have been proposed for inclusion in the DSM-5 and ICD-11.

[7][51] The analyses produced criteria that were the most accurate markers of bereaved individuals with painful, persistent, destructive PGD.

[7] The criteria for PGD have been validated and dozens of studies both internationally and domestically are being conducted, and published, that validate the PGD criteria in other cultures, kinship relationships to the deceased and causes of death (e.g. earthquakes, tsunami, war, genocide, fires, bombings, palliative and acute care settings).

It was understood to be closely related to, but distinguished from, normal grief and post traumatic stress disorder.

However, inclusion of PGD in the DSM-5 and ICD-11 was thought at risk of being misunderstood as medicalization of grief, reducing its dignity, turning love into pathology and implying that survivors should quickly forget and "get over" the loss.

In spite of this concern, studies have shown good accuracy for the ICD-11 and DSM-5-TR definitions, and that nearly all bereaved individuals who met the criteria for PGD were receptive to treatment and their families relieved to know they had a recognizable syndrome.