Science Communication Article Summaries
Our research assistants wrote summaries of recently published articles relevant to psychoneuroimmunology and our research lab to practice communicating scientific findings to a wider audience.
Trauma, psychological distress and markers of systemic inflammation among US women: A longitudinal study
Lawn, R. B., Murchland, A. R., Kim, Y., Chibnik, L. B., Tworoger, S. S., Rimm, E. B., Sumner, J. A., Roberts, A. L., Nishimi, K. M., Ratanatharathorn, A. D., Jha, S. C., Koenen, K. C., & Kubzansky, L. D. (2022). Psychoneuroendocrinology.
Summary by: Joelle Grossman
Researchers studied the link between trauma and depression and different markers related to physical health in the blood, such as factors that relate to risk to chronic illness. They studied this using middle-aged female nurses as participants and thought that those with higher levels of trauma and depression would also have higher amounts of these markers and they would increase more quickly over time. They gave participants questionnaires to screen for trauma, post-traumatic stress disorder, and depression. Then, they took their blood to test for these markers twice, 10-16 years apart. They controlled for many factors such as medications, smoking status, and time of year that the blood was drawn to attempt to rule out any confounding variables. The blood samples from groups of women with trauma or depression were compared to the groups without those conditions or symptoms. The same participants were also compared against themselves, using their first blood draw and their second. The results demonstrated that women with all three factors (trauma, post-traumatic stress disorder symptoms, and depression symptoms) had higher levels of the markers for chronic disease and inflammation than the control groups, which had no trauma or symptoms of either mental illness. Within participants, these markers increased more rapidly in those with all three mental factors than in those without them. In the future, this research can be expanded to examine if these factors go both ways and impact each other, or if it is just seen in this direction.
Summary by: Ana Beil
Researchers evaluated how PTSD and depression, separately and combined, related to inflammatory biomarker concentrations in blood. Data for this study was collected from participants over a 16-year timespan. PTSD and depression are highly comorbid and have been previously linked with higher levels of inflammation. Researchers hypothesized that individuals with high psychological distress would display higher levels of inflammatory biomarkers at baseline and a faster rate of increase of inflammatory biomarker concentration over time. Trauma exposure and PTSD symptoms were measured using modified versions of previously validated measures: the Brief Trauma Questionnaire and Breslau’s Short Screening Scale. Many potential covariates were considered in this research, including sociodemographic factors, blood collection factors, menopausal status, and biobehavioral factors. While it was not found that trauma exposure alone was associated with inflammatory biomarker concentrations, an association was found between higher distress and higher levels of inflammatory biomarker concentrations. This association was strongest amongst women experiencing multiple forms of distress and was attenuated when accounting for BMI. No link was found between distress score and rate of change in levels of inflammatory biomarkers. Strengths of this study include the separate examination of trauma and psychological distress and a longitudinal design. Limitations of this study include lack of determinate directionality, inclusion of both prospective and retrospective measurement, lack of generalizability due to all participants being female, and lack of information on timing of depression onset. Future studies could utilize the measurement of timing in order to better understand the relationship between trauma, distress, and inflammation. Understanding the connection between these three variables will lead to a stronger understanding of how psychological distress impacts health outcomes.
Sleep disturbance and activation of cellular and transcriptional mechanisms of inflammation in older adults.
Piber, D., Cho, J. H., Lee, O., Lamkin, D. M., Olmstead, R., & Irwin, M. R. (2022). Brain, Behavior, and Immunity.
Summary by: Allison Kim
The authors wanted to find out whether sleep disturbance among older adults is associated with increase in inflammation. Studying effects of sleep disturbance is important because as many as 50% of older adults struggle to get good sleep, which is linked to their energy level during the day and increased risk for many medical conditions.
Study 1 examined whether healthy older adults with poor sleep quality and those with good sleep quality had different production of cytokines after an immune response is triggered by lipopolysaccharide. Study 2 examined whether older adults with insomnia disorder and those without insomnia disorder had different regulation of transcription factors related to immune activation, sympathetic nervous system activity, hypothalamic-pituitary adrenal axis activity, and anti-viral responses.
In study 1, older adults with poor subjective sleep quality showed higher levels of cytokine production, but this occurred only when monocytes were stimulated by LPS. This indicates that poor sleep quality was not related to levels of baseline inflammation but to increase in response to outside invaders. Also, adjusting behavioral factors resulted in no significant effect of poor sleep quality on monocytic IL-6 production. In study 2, older adults with insomnia disorder showed higher transcription factor activity related to sympathetic nervous system function and lower transcription factor related to HPA axis function.
Three major limitations to this study are the smaller sample size, the lack of participants’ racial diversity, and self-reported sleep quality. Since the study was done on a small sample size of mostly white participants, it’s hard to say whether the results will apply to the general population.
Summary by: Emma Ferguson
Sleep disturbances are a common problem older adults face. Insufficient sleep may be associated with other age-related problems such as, cardiovascular diseases, stroke and major depressive disorder. The relationship between sleep disturbances and health-related adversities could be cause by inflammation. Researchers in this study speculate that sleep disturbance could be contributing to heightened levels of CRP and IL-6, both contributing to inflammation.
Two studies were conducted, one examining poor subjective sleep quality in older adults and another one examining insomnia in older adults. Both studies aimed to learn more about how different patterns of sleep interact with CTRA.
In the first study, older adults with poor sleep quality compared to adults with good sleep quality exhibited higher levels of inflammation. Additionally, study two also was consistent with the hypotheses made by the researchers. Older adults with insomnia had higher levels of transcription factors, which are present in the regulation of inflammatory responses. Adjusting for covariates or other behavioral factors attenuated the relationship with IL-6. This suggests the relationship between behavioral problems and poor sleep quality may be due to more factors than just inflammation.
Exercise after influenza or COVID-19 vaccination increases serum antibody without an increase in side effects.
Hallam J, Jones T, Alley J, Kohut ML. (2022). Brain, Behavior, and Immunity.
Summary by: Anna Casey
Improving the results of vaccination is an ongoing area of research. Exercise is one possible way of improving vaccination results that has been studied. If exercise is found to be effective, it is a very simple task to implement, and will be helpful in the public health field. The current study wanted to determine if exercising after receiving a vaccine increases antibody response. Antibodies are molecules in our bodies that help fight against foreign substances. Vaccines increase our antibody response to different diseases. Therefore, showing that there is increased antibody response to vaccines after implementing exercise would mean that the vaccine became more effective. The study had three different parts to it to determine the effect of exercise. In the first part, participants were given an influenza vaccine and then assigned to exercise for either 45 minutes, 90 minutes, or not at all. In the second part of the experiment, participants who received the COVID vaccine were then assigned to exercise for 90 minutes or not at all. Lastly, mice were given an influenza vaccine and exercised for different durations. In each of the experiments, antibody levels were measured.
Overall, the results of the study showed that exercise can increase antibody response after vaccination. We can look at the results of each part of the study to see how they support this conclusion. First, participants who received the influenza vaccine showed a greater antibody response after doing 90 minutes of exercise. Those in the 45 minute and no exercise groups did not see the same increase in antibody response. In the second experiment, participants who received the COVID vaccine and did exercise had a significantly greater antibody response than does who did not exercise. Lastly, mice who exercised for 90 minutes had a greater antibody response after four weeks than those who did 180 minutes of exercise or none at all. Results from all three of these parts of the study support the overall conclusion that 90 minutes of aerobic exercise can increase antibody response.
Childhood trauma, HPA axis activity and antidepressant response in patients with depression
Nikkheslat, N., McLaughlin, A. P., Hastings, C., Zajkowska, Z., Nettis, M. A., Mariani, N., Enache, D., Lombardo, G., Pointon, L., Cowen, P. J., Cavanagh, J., Harrison, N. A., Bullmore, E. T., Pariante, C. M., & Mondelli, V. (2020). Brain, Behavior, and Immunity
Summary by: Nathan Phillips
Despite the large prevalence of major depressive disorder (MDD) worldwide, about a third of patients do not respond to the current antidepressant medications on the market. Previous research suggests that these patients may have overactive hypothalamic-pituitary adrenal (HPA) axes, which leads to an increase in cortisol and inflammation markers. Some propose this comes from glucocorticoid resistance, a condition where the cortisol produced by the HPA-axis is unable to perform its normal purpose of going back and regulating the HPA-axis. Additionally, other studies have found that trauma in early childhood is not only a strong risk factor for MDD in adulthood, but that it may contribute to these HPA-axis dysfunctions. Therefore, the current study aims to determine if childhood trauma puts people at risk for increased cortisol production and glucocorticoid resistance, and if these abnormalities mean that those with childhood trauma are less likely to respond to antidepressant medication.
Splitting the participants into 4 groups, those who responded to treatment and were no longer depressed, those who did not respond to antidepressants and were depressed, those who were depressed but did not get treated with an antidepressant, and those with no depression, the researchers measured their inflammation and cortisol. They found that those with depression tended to have more childhood trauma than those without the disorder. However, those who did not respond to antidepressants tended to have the most trauma. Also, those who were not being treated with antidepressants had more cortisol and glucocorticoid resistance. Finally, the link between trauma and increased cortisol was only found in those who had glucocorticoid resistance.
Overall, the current study could provide beneficial information for those who suffer from depression. They confirmed that trauma in childhood is a strong risk factor for depression and can predict, to some extent, how one will respond to antidepressants. Therefore, the study implies that early intervention for children exposed to trauma should be used as a preventative measure. Finally, while they did not find that HPA-axis dysfunction or glucocorticoid resistance were necessarily predictive of poor response to antidepressants, they did find that trauma in childhood increased HPA-axis dysfunction when glucocorticoid resistance was present. This highlights a potential pathway for future treatment efforts to focus on, ultimately helping more people with depression.
Depression interacts with allostatic load to predict cognitive decline in middle age
Perlman G, Cogo-Moreira H, Wu CY, Herrmann N, Swardfager W. (2022). Psychoneuroendocrinology.
Summary by: Roma Dhingra
This study looked at the interaction that allostatic load can have on the association between prior depression and cognitive decline. Allostatic load can be defined as the cumulative burden that stress and life events have on the physical body. This concept ties in with the weathering hypothesis, which posits that stress causes physiological wear and tear. They used a public dataset, the Midlife in the United States study (MIDUS) to assess data from 704 participants. They used the Composite International Diagnostic Interview short-form to assess past depressive episodes, which they categorized as two-week periods with at least one of the two main symptoms of depression, depressed affect and anhedonia, along with four other symptoms including fatigue, appetite, and insomnia. They used biomarkers such as blood pressure, glucose levels, inflammation, etc. to measure allostatic load. They also conducted a variety of cognitive tests over the telephone to assess cognitive function. They found that allostatic load significantly moderated the negative association between depression and cognitive function. Therefore, those who had higher allostatic load were at greater risk of cognitive decline. These findings can be useful when considering dementia treatment and prevention.
Socioeconomic Status and Inflammation in Women with Early-stage Breast Cancer: Mediation by Body Mass Index
Pageot, Y., Stanton, A., Ganz, P., Irwin, M., Cole, S., Crespi, C., Breen, E., Kuhlman, K., Bower, J. (2022). Brain, Behavior, and Immunity.
Summary by: Shay Braksator
It has been shown in the past that socioeconomic status is linked to health. Generally, lower socioeconomic groups of people have a harder time recovering from illness or have poorer health outcomes compared to those in high SES groups. To explore at this relationship, researchers looked at how low vs. high SES relates to differences in inflammation in women with breast cancer. Women who received a recent, mild diagnosis and had not yet received treatment were included as participants. To collect this information, women reported their own SES, and a blood draw was used to assess for inflammation. BMI was also collected to assess whether it was on a pathway in the SES and inflammation relationship. The results found that only certain aspects of low SES showed a relationship with high inflammation such as education level but not income. Additionally, BMI was found as a link between SES measures and 3 out of the 4 measures of inflammation from the blood draw. One explanation for the results of this study may be that women with lower levels of education may face more barriers to seeking health care.
Reappraisal Enhances Memory Formation for a Stressful Episode
Lin, Li, Liang Zhang, and Lars Schwabe., (2022). Psychoneuroendocrinology.
Summary by: Nidhi Patel
Stress can lead to physical changes that can have an effect on cognitive processes. It can impact memory and mental health. However, people often respond to stress differently. One thing that may affect the stress response is emotion regulation- which is an individual's ability to control their emotional state. Two major strategies of emotion regulation that have been researched are reappraisal and suppression. Reappraisal is where emotion is controlled by redefining the situation that caused the emotional response. Suppression on the other hand is the active effort to hide the expression of an emotion. The current study aims to see how reappraisal and suppression strategies affect stress-related memory. To test this the study separated volunteers into 4 groups- a control group with no stress, a standard stress group, a reappraisal group, and a suppression group. The reappraisal group and suppression group were all taught how to use their specific strategies prior to the study and then were asked to complete stress tasks. They collected subjective measures of stress and cortisol measures (cortisol is a biomarker of stress). One week later the subjects completed tests assessing free recall and working memory.
The study found that the reappraisal strategy was associated with higher stress-related memory function. The reappraisal strategy group had increased levels of cortisol compared to the other stress groups on the first day of the study. This difference in cortisol level was no longer significant one week later. The reappraisal group was found to have significantly higher scores when asked to freely record objects they interacted with during the test on day 1. This finding suggests that short-term use of the reappraisal strategy was associated with better stress-related memory. One reason this may be the case is that the participants were asked to use reappraisal without being given extra training. This could have impacted their stress level due to the effort they had to exert to use the strategy.
Immune signature of multiple sclerosis-associated depression
Brasanac J, Ramien C, Gamradt S, Taenzer A, Glau L, Ritter K, Patas K, Agorastos A, Wiedemann K, Demiralay C, Fischer F, Otte C, Bellmann-Strobl J, Friese MA, Tolosa E, Paul F, Heesen C, Weygandt M, Gold SM. (2022). Brain, Behavior, and Immunity.
Summary by: Erin O’Donnell
The study looks at how major depressive disorder (MDD) and its link with inflammatory immune disorders. MDD is very common, and individuals with MDD may have a higher risk for conditions of pain and inflammation inside the body. By using magnetic resonance imaging technology (MRI) and looking at cell frequencies in blood levels, researchers examined how symptoms of MDD in individuals with multiple sclerosis (MS) can be linked through neuroinflammation. They used two different studies that had a total of 132 people in Germany. They only included people 18 years or older, those who met criteria for MS, and they had to be in a stable treatment for the last 3 months. They were put into two group those with and those without depression. Some of the reasons why they did not include people were if they were pregnant, any other mental disorder. In the end, they found that MS was associated with depressive symptoms. To be specific, those with depression had a low value of CD4+CCR7 cells in their body compared to those without depression. In order to confirm these findings researchers suggested using animal models could help.