Biological determinants of depression following bereavement

Types of bereavement and depressive symptoms among older adults: Does race/ethnicity matter?

AIM

To explore racial/ethnic differences in relation between types of bereavement and depressive symptoms among older adults in the USA.

METHODS

The sample limited to racially/ethnically diverse adults aged ≥55 (n = 879) was drawn from the third wave of the National Social Life, Health, and Aging Project (NSHAP). The NSHAP provides self-identified racial/ethnic categories (non-Hispanic Whites, Blacks, and Hispanics) of respondents who were categorized into three groups by experience of bereavement: non-loss, spousal loss, and parental loss. Using the weights, a two-way analysis of covariance with Bonferroni post-test was conducted to explore the main effect of types of loss and race/ethnicity and their interaction effects on depressive symptoms.

RESULTS

Spousal loss reported higher levels of depressive symptoms than non-loss or parental loss. Based on the interaction between types of loss and race/ethnicity; however, distinctive patterns were observed. Blacks and Hispanics who lose a parent reported significantly higher levels of depressive symptoms than non-Hispanic Whites did.

CONCLUSIONS

An increase in depressive symptoms after bereavement manifested distinctively based on racial/ethnic background and the relationship with the deceased. This implies that it is necessary to develop coping strategies concerning race/ethnicity and whom they lose. Geriatr Gerontol Int 2024; 24: 266-272.

Mindfulness-based cognitive therapy on bereavement grief: Alterations of resting-state network connectivity associate with changes of anxiety and mindfulness

Bereavement, the experience of losing a loved one, is one of the most catastrophic but inevitable events in life. It causes grief and intense depression‐like sadness. Recent studies have revealed the effectiveness and proficiency of mindfulness‐based cognitive therapy (MBCT) in emotional regulation among bereavement populations. MBCT improves the well‐being of the bereaved by enhancing cognitive performances. Regarding the neural correlates of bereavement grief, previous studies focused on the alleviation of emotion–cognition interferences at specific brain regions. Here, we hypothesized that the bereavement grief fundamentally triggers global alterations in the resting‐state brain networks and part of the internetwork connectivity could be reformed after MBCT intervention. We recruited 19 bereaved individuals who participated the 8‐week MBCT program. We evaluated (a) the large‐scale changes in brain connectivity affected by the MBCT program; as well as (b) the association between connectivity changes and self‐rated questionnaire. First, after MBCT, the bereaved individuals showed the reduction of the internetwork connectivity in the salience, default‐mode and fronto‐parietal networks in the resting state but not under emotional arousal, implying the alleviated attention to spontaneous mind wandering after MBCT. Second, the alterations of functional connectivity between subcortical (e.g., caudate) and cortical networks (e.g., cingulo‐opercular/sensorimotor) were associated with the changes of the mindfulness scale, the anxiety and the emotion regulation ability. In summary, MBCT could enhance spontaneous emotion regulation among the bereaved individuals through the internetwork reorganizations in the resting state.

Neuroendocrine mechanisms of grief and bereavement: A systematic review and implications for future interventions

Bereavement is associated with many negative behavioural, psychological and physiological consequences and leads to an increased risk of mortality and morbidity. However, studies specifically examining neuroendocrine mechanisms of grief and bereavement have yet to be reviewed. This systematic review is a synthesis of the latest evidence in this field and aims to draw conclusions about the implications of neurobiological findings on the development of new interventions. PRISMA guidelines for systematic reviews were used to search for articles assessing neuroendocrine correlates of grief. Findings were qualitatively summarised. The National Heart, Lung, and Blood Institute Study Assessment Tool was used to assess the quality of the included studies. Out of 460 papers, 20 met the inclusion criteria. However, most were of fair quality only. As a neuroendocrine marker, the majority of the studies reported cortisol as the outcome measure and found elevated mean cortisol levels, flattened diurnal cortisol slopes and higher morning cortisol in bereaved subjects. Cortisol alterations were moderated by individual differences such as emotional reaction to grief, depressive symptoms, grief severity, closeness to the deceased and age or gender. Research on neuroendocrine mechanisms of grief is still in its early stages regarding grief measures and the use and timing of neuroendocrine assessments. Most of the studies focus on cortisol as outcome, and only limited data exist on other biomarkers such as oxytocin. Future research might consider assessing a broader range of neuroendocrine markers and use longitudinal designs with a focus on the psychobiological reactions to loss. Based on this, individually tailored psychosocial interventions, possibly in the palliative care context, might be developed to prevent prolonged grief disorder.

The Psychobiology of Bereavement and Health: A Conceptual Review From the Perspective of Social Signal Transduction Theory of Depression

Losing a spouse is considered one of the most stressful life events a person can experience. Particularly in the immediate weeks and months after the loss, bereavement is associated with a significantly increased risk of morbidity and mortality. Despite an abundance of research aimed at identifying risk factors for adverse health outcomes following marital death, the mechanisms through which mental and physical health problems emerge following bereavement remain poorly understood. To address this issue, the present review examines several pathways that may link bereavement and health, including inflammation and immune dysregulation, genetic and epigenetic changes, gut microbiota activity, and biological aging. We then describe how these processes may be viewed from the perspective of the Social Signal Transduction Theory of Depression to provide a novel framework for understanding individual differences in long-term trajectories of adjustment to interpersonal loss. Finally, we discuss several avenues for future research on psychobiological mechanisms linking bereavement with mental and physical health outcomes.

Mindfulness Improves Emotion Regulation and Executive Control on Bereaved Individuals: An fMRI Study

The grief of bereavement is recognized as a severe psychosocial stressor that can trigger a variety of mental and physical disorders, and the long-lasting unresolved grief has a detrimental effect on brain functionality. Literature has documented mindfulness-based cognitive therapy (MBCT) as an efficient treatment for improving well-being, specifically related to the mood and cognition, in a variety of populations. However, little attention has been devoted to neural mechanisms with regard to bereaved individuals' cognition after MBCT intervention. In this study, we recruited 23 bereaved participants who lost a significant relative within 6 months to 4 years to attend 8-week MBCT course. We used self-reporting questionnaires to measure emotion regulation and functional magnetic resonance imaging (fMRI) with the numerical Stroop task to evaluate the MBCT effect on executive control among the bereaved participants. The self-reported questionnaires showed improvements on mindfulness and reductions in grief, difficulties in emotion regulation, anxiety, and depression after the MBCT intervention. The fMRI analysis demonstrated two scenarios: (1) the activity of the fronto-parietal network slightly declined accompanied with significant improvements in the reaction time of incongruent trials; (2) the activities in the posterior cingulate cortex and thalamus were positively associated with the Texas Revised Inventory of Grief, implying emotional interferences on cognitive functions. Results indicated that MBCT facilitated the executive control function by alleviating the emotional interferences over the cognitive functions and suggested that the 8-week MBCT intervention significantly improved both executive control and emotion regulation in bereaved individuals.

Association between the employment status and the presence of depressive symptoms in men and women in Mexico

Abstract: This study aims to estimate the relationship between employment status and depressive symptoms among Mexican adults, as well as to explore its differential effect by gender. Cross-sectional study of 36,516 adults between 20 and 59 years of age taken from the 2012 Mexican National Health and Nutrition Survey. Depressive symptoms were evaluated using the Center for Epidemiologic Studies Depression Scale (CES-D), and the employment status was determined a week before the survey. Logistic regression models were stratified by gender and education level and adjusted by sociodemographic and health-related conditions to estimate the association between depressive symptoms and employment status. The prevalence of clinically depressive symptoms was 7.59% for men and 18.62% for women. In the case of men, those who were unemployed were more likely to present depressive symptoms (OR = 1.66; 95%CI: 1.08-2.55) than those who were working. For women, employment status is not associated with the presence of depressive symptoms, except in students (OR = 1.57; 95%CI: 1.02-2.43) compared with those who were working. In both genders, disability preventing one from working was associated with depressive symptoms. Although being employed has been reported to be associated with lower levels of psychiatric morbidity, the estimated effect is different for men and women. Occupational health policies should consider these conditions.

Repatriation is associated with isthmus cingulate cortex reduction in community-dwelling elderly

OBJECTIVES

The impact of stressful life events (SLEs) on brain anatomy is poorly understood, particularly its long-term neural consequences. We tested the hypothesis that a serious SLE (repatriation of French citizens living in Algeria in 1962) is associated with changes in brain regions previously implicated in psychopathology (hippocampus, amygdala, corpus callosum, prefrontal cortex, anterior, posterior and isthmus cingulate cortex (ICC)) in a large elderly population.

METHODS

Structural magnetic resonance imaging was used to acquire anatomical scans from 82 subjects repatriated from Algeria and 339 subjects without this experience or any other trauma. We derived quantitative regional estimates of subcortical volume using FreeSurfer Software. The General Linear Model was used to test the association between repatriation and changes in brain volume adjusted for confounders (gender, age, education, total brain volume, traumatic brain injury, Mini Mental State Examination score at baseline, current and lifetime major depression and recent SLEs).

RESULTS

Repatriation to France was associated with reduced volume in a number of areas; however, only left and right ICC survived to false discovery rate correction.

CONCLUSIONS

In the elderly a previous (approximately 40 years before) serious SLE could be associated with long-term volume reduction in the ICC, independently of psychopathology.

Spousal bereavement is associated with more pronounced ex vivo cytokine production and lower heart rate variability: Mechanisms underlying cardiovascular risk?

The loss of a spouse is a highly stressful event that puts people at excess risk of mortality. Excess mortality among those who are widowed is highest in the first six months after the death of a spouse and decreases over time. Heart disease accounts for the largest proportion of these deaths. The psychological stress associated with stressful life events can enhance inflammation and lower heart rate variability (HRV). Both lower HRV and higher inflammation are risk factors for cardiovascular morbidity and mortality. Thirty-two recently bereaved individuals (Mean = 89.68 days since death, SD = 17.09) and 33 age-matched comparisons completed a blood draw, EKG, and self-report questionnaires. In both adjusted and unadjusted models, spousal bereavement was associated with enhanced pro-inflammatory cytokine production by in vitro lipolysaccharide-stimulated peripheral blood leukocytes. Moreover, spousal bereavement was associated with lower HRV in comparison to the comparison group. This study is the first to demonstrate that bereavement is associated with a more pronounced ex vivo cytokine production and lower HRV in a population that exclusively consisted of widows and widowers. These findings add to the growing literature revealing the mechanisms that underlie bereavement-related cardiovascular problems. Future longitudinal studies are needed to determine the temporal relation between these risks. Understanding the biological mechanisms that underlie this stressful life event could allow researchers to create therapeutic targets for interventions to reduce or prevent the toll of a "broken heart."

Depression subtyping based on evolutionary psychiatry: Proximate mechanisms and ultimate functions

Major depressive disorder constitutes one of the leading causes of disability worldwide. However, it is not a unitary disease-it is a heterogeneous syndrome, with patients differing remarkably in symptom profile, pathophysiology and treatment responsiveness. Previous attempts to subtype major depressive disorder have showed limited clinical applicability. We present a classification of major depressive disorder episodes based on the proximate mechanisms that led to the original mood change that caused the depressive episode. We identify discrete depression subtypes that are induced by: 1) infection, 2) long-term stress, 3) loneliness, 4) traumatic experience, 5) hierarchy conflict, 6) grief, 7) romantic rejection, 8) postpartum events, 9) the season, 10) chemicals, 11) somatic diseases and 12) starvation. We further examine the ultimate functions of these subtypes and show that not all types of mood changes that trigger depression are adaptive. Instead, some are clearly maladaptive and some are byproducts of other adaptations. In modern societies, low mood after adverse life events may turn into a pathological depressive state. Modern lifestyle increases susceptibility to inflammatory dysregulation and chronic stress, both of which increase the amount of proinflammatory cytokines in peripheral blood, leading to low mood and sickness behaviour. Proinflammatory cytokines may aggravate the previously adaptive short-term mood changes to a chronic maladaptive depressive state by preventing the normalization of mood after adverse life events. Subtyping depression enables an effective and intelligent long-term treatment of patients in each subtype by treating the underlying causes of depression.

Oxytocin and Social Relationships: From Attachment to Bond Disruption

Social relationships throughout life are vital for well-being and physical and mental health. A significant amount of research in animal models as well as in humans suggests that oxytocin (OT) plays an important role in the development of the capacity to form social bonds, the mediation of the positive aspects of early-life nurturing on adult bonding capacity, and the maintenance of social bonding. Here, we focus on the extensive research on a socially monogamous rodent model organism, the prairie vole (Microtus ochrogaster). OT facilitates mating-induced pair bonds in adults through interaction with the mesolimbic dopamine system. Variation in striatal OT receptor density predicts resilience and susceptibility to neonatal social neglect in female prairie voles. Finally, in adults, loss of a partner results in multiple disruptions in OT signaling, including decreased OT release in the striatum, which is caused by an activation of the brain corticotropin releasing factor (CRF) system. The dramatic behavioral consequence of partner loss is increased depressive-like behavior reminiscent of bereavement. Importantly, infusions of OT into the striatum of adults prevents the onset of depressive-like behavior following partner loss, and evoking endogenous OT release using melanocortin agonists during neonatal social isolation rescues impairments in social bonding in adulthood. This work has important translational implications relevant to the disruptions of social bonds in childhood and in adults.

In vivo study on the neurotransmitters and their metabolites change in depressive disorder rat plasma by ultra high performance liquid chromatography coupled to tandem mass spectrometry

A sensitive and versatile, ultra-high performance, liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method coupled to pre-column derivatization for the simultaneous determination of 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), dopamine (DA), norepinephrine (NE), homovanillic acid (HVA), γ-aminobutyric acid (GABA) and glutamic acid (Glu) was developed and validated in rat plasma. The analytes were dansylated under strong alkaline conditions after protein precipitation extraction, which were analyzed on a BEH C18 column using a gradient elution. The lower limit of quantification (LLOQ) values for 5-HT, 5-HIAA, DA, NE, HVA, GABA and Glu were 1.00, 1.00, 0.991, 0.992, 1.02, 1000, and 5030 pmol/mL, respectively. Good linearity was obtained (r > 0.99) and the intra- and inter-day precisions of the method (relative standard deviation, RSD%) were lower than 12%. The method was novel, sensitive and specific which can provide an alternative method for the quantification of neurotransmitters and their metabolites in plasma samples.