Common phenomena of the grief experience of adults, identified through many research studies,^{(12, 13 and 14)} relate to similar domains influenced by developmental trajectories, through childhood and adolescence. Adult studies indicate consistent patterns: numbness, disbelief; yearning, angry protest, and ‘searching’ behaviours representing separation distress; and sadness with reviewing of memories of the lost relationship, with a range of associated emotions; progressive acceptance of the death and changed circumstances, sometimes referred to as resolution.

Bonanno⁽¹⁴⁾ has shown that resilient trajectories, defined by low overall distress, are common. Other transient phenomena described by clinicians working with bereaved people⁽¹⁵⁾ include: identificatory symptoms, reflecting the deceased’s illness; a sense of the deceased’s ongoing at presence, at times as though seeing the face, hearing the voice, or feeling the touch of the dead person. ‘Yearning’ is considered to be the most pathognomic of these grief phenomena, which usually settle over the first year, but may continue, triggered by anniversaries, or specific memories. Older people who have had a long relationship with a spouse may continue this relationship in their minds for the comfort of ‘talking’ with the person, and a need for the ongoing closeness.⁽¹⁶⁾

Recent research⁽¹⁷⁾ has modelled sequential peaks of the reactive phenomena: disbelief, yearning, anger, and depression, which bereaved people more usually describe as sadness. Grief may be a precipitant of depression in those with pre-existing or bereavement-related vulnerabilities and the differentiation of normal and more pathological forms of grief from depression is important clinically.^(15,18) Intense grief and the peaks of distress identified above do not usually continue beyond the first 4-6 months.^(12,13) Continuing ‘acute’ grief beyond this time suggests the possibility of pathological response, as do other risk indicators, although some phenomena may continue intermittently for many years. Comparative studies have demonstrated that the intensity of adult grief is likely to be greatest for the death of a child, then spouse, or partner, then parent.^(12,19)

Recent research has examined the neurobiology of grief through studies using functional magnetic resonance imaging of grief (20) and brain activity in wom°en grieving the break-up of a romantic relationship.⁽²¹⁾ Workers have attempted to develop a theoretical model based on a wide range of relevant data, encompassing a ‘neurobiopsychosocial’ framework for sadness and loss.⁽²²⁾ Stress hormones⁽²³⁾ and psychoimmune function is a further area of research. A comprehensive model integrating the relevant research findings is yet to be established.

Pre–existing vulnerabilities that may influence the course and outcome have been reviewed alongside other risk factors.⁽²⁴⁾ These include personality vulnerabilities related to relationship styles such as avoidant and insecure attachments. Genetic factors do not appear to have been directly studied, but it is likely that the short allele of the serotonin gene promoter polymorphism of 5HTTLPR which influences response to adversity may contribute, through gene-environment interactions.⁽²⁵⁾ Prior loss and adverse experiences may add vulnerability, for instance multiple losses faced by indigenous peoples, with loss of culture, land, and loved ones, with multiple premature deaths and separations.⁽²⁶⁾ Separation anxiety in childhood, as well as pre-existing psychiatric disorder, family psychiatric disorder, and substance abuse may add to vulnerability. Successful negotiation of earlier losses, mature defence styles, and optimism may be protective.

The nature of the lost relationship has been identified in a number of studies as being a significant factor.^(15,27) The special relationship between parent and child is associated with greater vulnerabilities, including increased risk of psychiatric hospitalization and even death by suicide. Patterns of distress differ by gender with stillbirth, neonatal deaths, and sudden infant death syndromes, perhaps suggesting different attachment patterns.⁽²⁸⁾ The death of an adolescent child is not infrequently by accident, suicide, or risk-taking with illicit drugs, bringing the extra complexities of adaptation for the grieving parents.

A great deal of research has explored the grief associated with the death of a partner or spouse both young and old. High levels of dependence and ambivalence have been shown to complicate grief and to be associated with more difficult bereavement,^(15,27) and prolonged or complicated grief may be more likely.

Family members may have different relationships with the deceased, and thus varying patterns and trajectories of grief, which may cloud the recognition of children’s and others needs.