Adversity and inflammation among adolescents: a possible pathway to long-term health risk

Moving toward affective immunology: Legacy and future directions

The term "affective immunology" has recently been used to denote a field focused on the interplay between affective processes (including mood states, specific emotions, and regulatory processes) and various aspects of immune function. The overarching goals of this commentary are a) to provide historical underpinnings of this field with a focus on the profound impact of the work of Janice Kiecolt-Glaser, who is further honored in this special issue, b) to review important off-shoots of her legacy work in this domain, and c) to highlight important future directions for the field. Kiecolt-Glaser's work laid much of the foundation for affective immunology, with groundbreaking research related to depression, hostility and dyadic interactions, loneliness, and other affective patterns, often in the context of holistic models, novel experimental designs, and interventions. Her former mentees (and many of their mentees) have carried on her legacy in these domains, in ways that continue to advance appreciation of how affective processes relate to immune function. There are numerous remaining questions for the field to pursue, including better understanding of the role of emotion regulation, emotional reactivity and recovery, restorative processes, affective variability, and developmental and dynamic social processes. Such work will require greater use of longitudinal and within-person approaches and/or examination of processes in daily life, as well as models that account for interactive and reciprocal processes and which integrate behavior, social context, sociocultural factors, individual differences, and other aspects of health. As more work in these domains continues, building on Kiecolt-Glaser's rich legacy, we move toward the emergence of affective immunology as an important subfield in the domain of psychoneuroimmunology, one which will offer more nuanced understanding of the role of affective processes in immune health.

The impact of forced displacement: trauma, increased levels of inflammation and early presentation of diabetes in women Syrian refugees

BACKGROUND

Forced displacement and war trauma cause high rates of post-traumatic stress, anxiety disorders and depression in refugee populations. We investigated the impact of forced displacement on mental health status, gender, presentation of type 2 diabetes (T2D) and associated inflammatory markers among Syrian refugees in Lebanon.

METHODS

Mental health status was assessed using the Harvard Trauma Questionnaire (HTQ) and the Hopkins Symptom Checklist-25 (HSCL-25). Additional metabolic and inflammatory markers were analyzed.

RESULTS

Although symptomatic stress scores were observed in both men and women, women consistently displayed higher symptomatic anxiety/depression scores with the HSCL-25 (2.13 ± 0.58 versus 1.95 ± 0.63). With the HTQ, however, only women aged 35-55 years displayed symptomatic post-traumatic stress disorder (PTSD) scores (2.18 ± 0.43). Furthermore, a significantly higher prevalence of obesity, prediabetes and undiagnosed T2D were observed in women participants (23.43, 14.91 and 15.18%, respectively). Significantly high levels of the inflammatory marker serum amyloid A were observed in women (11.90 ± 11.27 versus 9.28 ± 6.93, P = 0.036).

CONCLUSIONS

Symptomatic PTSD, anxiety/depression coupled with higher levels of inflammatory marker and T2D were found in refugee women aged between 35 and 55 years favoring the strong need for psychosocial therapeutic interventions in moderating stress-related immune dysfunction and development of diabetes in this subset of female Syrian refugees.

Executive Control, Cytokine Reactivity to Social Stress, and Depressive Symptoms: Testing the Social Signal Transduction Theory of Depression

Social Signal Transduction Theory of Depression hypothesizes that social stress upregulates inflammatory activity, which in turn contributes to depression for some individuals. However, the specific cognitive processes underlying social stress-induced increases in inflammatory activity remain unclear. We addressed this issue by examining two separate relations: (1) between executive control measured following a laboratory-based social stress induction and individuals' pro-inflammatory cytokine responses to the same stress induction and (2) between pro-inflammatory cytokine responses and participants' depressive symptom levels. Healthy young participants (Mage = 18.58 years old) were randomly assigned to either a stress condition or control condition. Executive control, and the inflammatory cytokines interleukin-1β, interleukin-6, and tumor necrosis factor-α, were measured before and after the social stress induction or control task. Regression analyses (stress condition, n = 20; control condition, n = 16) demonstrated that in the stress condition only, greater increases in interleukin-6 were associated with more depressive symptoms. Additional analyses in the stress condition (n = 16) indicated that greater impairment in executive control following the social stress induction was related to greater social stress-induced increases in interleukin-6. These findings are consistent with Social Signal Transduction Theory of Depression and with the hypothesis that impairment in executive control during times of stress may be one process that contributes to stress-induced inflammatory activity, which may in turn increase risk for depression.Lay SummarySocial Signal Transduction Theory of Depression hypothesizes that social stress upregulates inflammatory activity, which in turn contributes to depression, and that cognitive processes play a role in structuring these effects. Consistent with this theory, greater social stress-induced increases in the inflammatory cytokine interleukin-6 were associated with more depressive symptoms. In addition, greater impairment in executive control following the social stress induction was related to greater social stress-induced increases in interleukin-6, highlighting potential links between social stress, cognition, inflammation, and depression.

Family Member Deaths in Childhood Predict Systemic Inflammation in Late Life

Biological and epidemiological evidence has linked early-life psychosocial stress with late-life health, with inflammation as a potential mechanism. We report here the association between familial death in childhood and adulthood and increased levels of high-sensitivity C-reactive protein (CRP), a marker of systemic inflammation. The Cache County Memory Study is a prospective study of persons initially aged 65 and older in 1995. In 2002, there were 1,955 persons in the study with data on CRP (42.3 percent male, mean [SD] age = 81.2 [5.8] years), linked with objective data on family member deaths. Using logistic regression, high (> 10 mg/L) versus low (≤ 10 mg/L) CRP was regressed on cumulative parental, sibling, spouse, and offspring deaths during childhood and during early adulthood, adjusted for family size in each period (percentage family depletion; PFD). Findings revealed PFD during childhood to be significantly associated with CRP (OR = 1.02, 95% CI [1.01, 1.04]). Individuals with two or more family deaths were 79 percent more likely to have elevated CRP than those with zero family deaths (OR = 1.79, 95% CI [1.07, 2.99]). Early adulthood PFD was not related to CRP. This study demonstrates a link between significant psychosocial stress in early life and immune-inflammatory functioning in late life, and suggests a mechanism explaining the link between early-life adversity and late-life health.

Stress- and PTSD-associated obesity and metabolic dysfunction: a growing problem requiring further research and novel treatments

Posttraumatic stress disorder (PTSD) is a growing public health concern. More recently, evidence has indicated that PTSD leads to obesity and associated metabolic dysfunction. Possible mechanisms of this link are through dysfunction of the hypothalamic-pituitary-adrenal axis and related moderation of appetite hormones and neural activity, leading to changes in consumptive behaviors. Although research has been examining associations between PTSD and obesity, diabetes, cardiovascular disease, and metabolic syndrome, future research should delineate potential mechanisms for these associations and develop targeted treatments to reduce these metabolic outcomes.