Long-term immune-endocrine effects of bereavement: relationships with anxiety levels and mood

Abstract 

Psychological, endocrine and immune parameters were measured over a 6-month period in 14 healthy subjects who underwent an unpredictable acute emotional stress (e.g. sudden death of a loved one) compared with 14 controls who did not. Probands were profoundly stressed as assessed 10 days after bereavement by their scores on the Hamilton Rating Scales of Anxiety and Depression, adrenocorticotropin and cortisol plasma concentrations, and non-suppression in response to dexamethasone. Functional alterations of immune parameters, such as responsiveness of peripheral blood lymphocytes to mitogens, were found 40 days after bereavement. Despite a normal number of circulating lymphocyte subsets, the functional activity of natural killer (NK) cells was markedly reduced at day 40. Changes in the intracellular concentration of β-endorphin in peripheral blood mononuclear cells correlated with anxiety and depression scores. Controls showed no changes in psychometric, endocrine and immune measures during the 6-month study. Cluster analysis revealed two groups of bereaved subjects with different patterns of immune and endocrine changes: (1) Five subjects, characterized by harm-avoidant temperament and long-lasting dysphoric mood, showed reduced responsiveness of peripheral blood lymphocytes to mitogens, decreased NK cell activity and non-suppression in response to dexamethasone that persisted for 6 months. (2) Nine subjects showed significant changes only during the early phase after bereavement. Our data suggest that the immunological consequences of stress do not simply overlap with psychological and endocrine alterations, and are particularly severe and long-lasting in a subgroup of subjects, indicating the importance of individual variability in the capacity to cope with stress.

Keywords: Bereavement, Psychological stress, β-endorphin, Anxiety, Depression, Natural killer cells, Neuro-immunomodulation, Corticotropin, Hydrocortisone, Dexamethasone