Healthcare personnel experienced unprecedented stressors and risk factors for burnout, anxiety, and depression during the COVID-19 pandemic. This may have been particularly true for spiritual health clinicians (SHCs), also referred to as healthcare chaplains. We administered a daily pulse survey that allowed SHCs to self-report burnout, depression, and well-being, administered every weekday for the first year of the pandemic. We used a series of linear regression models to evaluate whether burnout, depression, and well-being were associated with local COVID-19 rates in the chaplains’ hospital system (COVID-19 admissions, hospital deaths from COVID-19, and COVID-19 ICU census). We also compared SHC weekly rates with national averages acquired by the U.S. Census Bureau’s Household Pulse Survey (HPS) data during the same timeframe. Of the 840 daily entries from 32 SHCs, 90.0% indicated no symptoms of burnout and 97.1% were below the cutoff for depression. There was no statistically significant relationship between any of the COVID-19 predictors and burnout, depression, or well-being. Mean national PHQ-2 scores were consistently higher than our sample’s biweekly means. Understanding why SHCs were largely protected against burnout and depression may help in addressing the epidemic of burnout among healthcare providers and for preparedness for future healthcare crises.
Circulating concentrations of interleukin (IL)-6, an inflammatory biomarker widely assessed in humans to study the inflammatory response to acute psychological stress, have for decades been quantified using enzyme-linked immunosorbent assay (ELISA). However, biobehavioral researchers are increasingly using cytokine multiplex assays instead of ELISA to measure IL-6 and other cytokines. Despite this trend, multiplex assays have not been directly compared to ELISA for their ability to detect subtle stress-induced changes of IL-6. Here, we tested the prediction that a high-sensitivity multiplex assay (human Magnetic Luminex Performance Assay, R&D Systems, Minneapolis, MN) would detect changes in IL-6 as a result of acute stress challenge in a manner comparable to high-sensitivity ELISA. Blood was collected from 12 healthy adults immediately before and then 90 and 210 min after the start of the Trier Social Stress Test (TSST), an acute laboratory psychosocial stress challenge. In addition to quantifying IL-6 concentrations in plasma with both multiplex and ELISA, we also assessed concentrations of tumor necrosis factor-alpha, IL-8, IL-10, IL-5, and IL-2 with multiplex. The multiplex detected IL-6 in all samples. Concentrations strongly correlated with values determined by ELISA across all samples (r = 0.941, p <.001) as well as among samples collected at individual TSST time points. IL-6 responses to the TSST (i.e. area under the curve) captured by multiplex and ELISA were also strongly correlated (r s= 0.937, p <.001). While other cytokines were detected by multiplex, none changed as a result of TSST challenge at time points examined. These results suggest high-sensitivity magnetic multiplex assay is able to detect changes in plasma concentrations of IL-6 as a result of acute stress in humans.
Major medical illnesses are associated with increased risk for depression and alterations in hypothalamic–pituitary–adrenal (HPA) axis function. Pathophysiological processes such as inflammation that occur as a part of medical illnesses and their treatments have been shown to cause depressive symptoms, and may also affect the HPA axis. We previously reported that patients with hepatitis C virus chronically administered interferon (IFN)-alpha develop increased evening plasma cortisol concentrations and a flattened diurnal cortisol slope, which correlated with increased tumor necrosis factor (TNF) and its soluble receptor 2 (sTNFR2). Increased TNF and sTNFR2 were further correlated with depression and fatigue scores. The current study examined whether flattened cortisol slope might be secondary to reduced glucocorticoid receptor (GR) sensitivity, by measuring glucocorticoid negative feedback to dexamethasone (DEX) administration followed by corticotropin releasing hormone (CRH) challenge. In an exploratory analysis, 28 male and female patients with hepatitis C virus were studied at baseline (Visit 1) and after 12 weeks (Visit 2) of either IFN-alpha plus ribavirin (n = 17) or no treatment (n = 11). Patients underwent dexamethasone DEX–CRH challenge, neuropsychiatric assessments, and measurement of plasma TNF and sTNFR2 during each visit. IFN-alpha did not affect neuroendocrine responses following CRH but did increase post-DEX cortisol, which was correlated with flattening of the diurnal cortisol slope (r = 0.57, p = 0.002) and with increased depression scores (r = 0.38, p = 0.047). Furthermore, the change in post-DEX cortisol was associated with IFN-alpha-induced increase in sTNFR2 (r = 0.51, p = 006), which was in turn correlated with depression (r = 0.63, p < 0.001) and fatigue (r = 0.51, p = 0.005) scores. Whereas the relationship between sTNFR2 and depression scores were independent of the change in post-DEX cortisol, the correlation between post-DEX cortisol and depression scores was not significant when controlling for sTNFR2. These findings suggest that inflammation induced in patients with hepatitis C virus during IFN-alpha therapy precipitates decreased GR sensitivity to lead to a flattened diurnal cortisol slope. Decreased GR sensitivity may in turn further increase inflammation and its ultimate effects on behavior. Treatments that target inflammation and/or GR sensitivity may reduce depressive symptoms associated with medical illnesses.
Given the manifold ways that depression impairs Darwinian fitness, the persistence in the human genome of risk alleles for the disorder remains a much debated mystery. Evolutionary theories that view depressive symptoms as adaptive fail to provide parsimonious explanations for why even mild depressive symptoms impair fitness-relevant social functioning, whereas theories that suggest that depression is maladaptive fail to account for the high prevalence of depression risk alleles in human populations. These limitations warrant novel explanations for the origin and persistence of depression risk alleles. Accordingly, studies on risk alleles for depression were identified using PubMed and Ovid MEDLINE to examine data supporting the hypothesis that risk alleles for depression originated and have been retained in the human genome because these alleles promote pathogen host defense, which includes an integrated suite of immunological and behavioral responses to infection. Depression risk alleles identified by both candidate gene and genome-wide association study (GWAS) methodologies were found to be regularly associated with immune responses to infection that were likely to enhance survival in the ancestral environment. Moreover, data support the role of specific depressive symptoms in pathogen host defense including hyperthermia, reduced bodily iron stores, conservation/withdrawal behavior, hypervigilance and anorexia. By shifting the adaptive context of depression risk alleles from relations with conspecifics to relations with the microbial world, the Pathogen Host Defense (PATHOS-D) hypothesis provides a novel explanation for how depression can be nonadaptive in the social realm, whereas its risk alleles are nonetheless represented at prevalence rates that bespeak an adaptive function.
Summary
Meditation practices may impact physiological pathways that are modulated by stress and relevant to disease. While much attention has been paid to meditation practices that emphasize calming the mind, improving focused attention, or developing mindfulness, less is known about meditation practices that foster compassion. Accordingly, the current study examined the effect of compassion meditation on innate immune, neuroendocrine and behavioral responses to psychosocial stress and evaluated the degree to which engagement in meditation practice influenced stress-reactivity. Sixty-one healthy adults were randomized to 6 weeks of training in compassion meditation (n=33) or participation in a health discussion control group (n=28) followed by exposure to a standardized laboratory stressor (Trier Social Stress Test [TSST]). Physiologic and behavioral responses to the TSST were determined by repeated assessments of plasma concentrations of interleukin (IL)-6 and cortisol as well as total distress scores on the Profile of Mood States (POMS). No main effect of group assignment on TSST responses was found for IL-6, cortisol or POMS scores. However, within the meditation group, increased meditation practice was correlated with decreased TSST-induced IL-6 (rp =-0.46, p=0.008) and POMS distress scores (rp =-0.43, p=0.014). Moreover, individuals with meditation practice times above the median exhibited lower TSST-induced IL-6 and POMS distress scores compared to individuals below the median, who did not differ from controls. These data suggest that engagement in compassion meditation may reduce stress-induced immune and behavioral responses, although future studies are required to determine whether individuals who engage in compassion meditation techniques are more likely to exhibit reduced stress reactivity.
The amygdala has been repeatedly implicated in emotional processing of both positive and negative-valence stimuli. Previous studies suggest that the amygdala response to emotional stimuli is lower when the subject is in a meditative state of mindful-attention, both in beginner meditators after an 8-week meditation intervention and in expert meditators. However, the longitudinal effects of meditation training on amygdala responses have not been reported when participants are in an ordinary, non-meditative state. In this study, we investigated how 8 weeks of training in meditation affects amygdala responses to emotional stimuli in subjects when in a non-meditative state. Healthy adults with no prior meditation experience took part in 8 weeks of either Mindful Attention Training (MAT), Cognitively-Based Compassion Training (CBCT; a program based on Tibetan Buddhist compassion meditation practices), or an active control intervention. Before and after the intervention, participants underwent an fMRI experiment during which they were presented images with positive, negative, and neutral emotional valences from the IAPS database while remaining in an ordinary, non-meditative state. Using a region-of-interest analysis, we found a longitudinal decrease in right amygdala activation in the Mindful Attention group in response to positive images, and in response to images of all valences overall. In the CBCT group, we found a trend increase in right amygdala response to negative images, which was significantly correlated with a decrease in depression score. No effects or trends were observed in the control group. This finding suggests that the effects of meditation training on emotional processing might transfer to non-meditative states. This is consistent with the hypothesis that meditation training may induce learning that is not stimulus- or task-specific, but process-specific, and thereby may result in enduring changes in mental function.
Evidence suggests several causes for depression, including traumatic life events, disease, poison, and nutritional deficiencies. Many of these causes are associated with elevated levels of inflammatory biomarkers in the blood, which may in turn lead to inflammatory changes in the brain. Our authors examine what the latest research reveals about the link between inflammation in the brain and depression, and how a better understanding of that link can play a critical first step in the personalization of care.
Crosstalk between inflammatory pathways and neurocircuits in the brain can lead to behavioural responses, such as avoidance and alarm, that are likely to have provided early humans with an evolutionary advantage in their interactions with pathogens and predators. However, in modern times, such interactions between inflammation and the brain appear to drive the development of depression and may contribute to non-responsiveness to current antidepressant therapies. Recent data have elucidated the mechanisms by which the innate and adaptive immune systems interact with neurotransmitters and neurocircuits to influence the risk for depression. Here, we detail our current understanding of these pathways and discuss the therapeutic potential of targeting the immune system to treat depression.