Early Environments on Health Trajectories
Early-Life Psychological Stress and Long-Term Health Effects
Inflammation is thought to be a key pathway linking childhood stress with health problems, yet the available research has not been comprehensively evaluated to further understand this relationship. In Psychological Bulletin, IPR health psychologists Edith Chen and Greg Miller, graduate research assistant Phoebe Lam, and former IPR post-doctoral fellow Jessica Chiang of Georgetown University seek to answer three questions: How the relationship between childhood stress and inflammation changes over the lifespan, if certain childhood stressors affect inflammation differently, and which inflammation components are associated with childhood stress. Their meta-analysis examined 187 studies from the last two decades that investigated the relationship between childhood stress and inflammation. The researchers find that as people age, the relationship between childhood stress and inflammation gets stronger, suggesting that effects of early stress grow over time. They also find that children exposed to severe or chronic psychological stress, such as living in a violent neighborhood or having a clinically depressed parent, had higher levels of inflammation. The meta-analysis found that different components of inflammation are similarly associated with stress. These findings better establish the link between inflammation and stress-induced health issues and identify inflammation as a key target to relieve childhood stress effects. These findings can help determine what interventions, especially psychological ones, to provide, who might benefit from them, and if certain stressful experiences should be addressed. Edith Chen is the John D. and Catherine T. MacArthur Professor of Psychology and Greg Miller is the Louis W. Menk Professor of Psychology.
Childhood Infections and Biological Aging
Human life expectancy has doubled over the last 200 years, but we do not really understand why. Though researchers have studied how infants’ environments affect their health as they age, the role infectious diseases play in the pace of biological aging is unclear. In the American Journal of Human Biology, IPR anthropologists Thomas McDade and Christopher Kuzawa, along with their colleagues, investigate this connection. Using data from the Cebu Longitudinal Health and Nutrition Survey in the Philippines, they examine 1,450 participants born in 1983–84 who were 20–21 years old in 2005 when blood samples were taken from which DNA was extracted and analyzed. Additionally, they also had health history data for their first two years from in-home interviews. Three markers, which indicate epigenetic—or biological—age, were measured in the DNA samples. The researchers’ analysis showed that individuals who had more infections by age 2 had a younger biological age in adulthood. The authors call for more research to investigate the immune mechanisms affected by early exposure to infections and how they might influence aging. McDade is Carlos Montezuma Professor of Anthropology, and Kuzawa is John D. MacArthur Professor of Anthropology.
Legacies of Apartheid and Psychiatric Illness
Apartheid has had lasting consequences in South Africa, including widespread poverty, racial discrimination, and class inequality. In his study published in The Journal of Child Psychology and Psychiatry, IPR anthropologist Christopher Kuzawa and his colleagues investigate whether prenatal stress experienced due to intergenerational trauma, meaning the effects that the trauma experienced by one generation has on subsequent generations, under apartheid impacted the mental health of children born as apartheid ended. The researchers used a longitudinal study among 304 pregnant women enrolled in 1990 in the city of Soweto-Johannesburg, a major center of violence during apartheid. Researchers questioned the women to determine their level of social adversity during their pregnancy. When their children reached ages 17 to 18, their mental health was assessed using a General Health Questionnaire (GHQ), which is a psychological screener that assesses mental health based on four scales. The researchers find that while prenatal stress caused by apartheid did not correlate with a direct increase in mental health issues in adolescents, it did cause them to be more vulnerable to mental health issues, especially if they experienced household adversity. Additionally, their research established the effects of maternal age, social support, and past household adversity on the mental health of children at age 17 or 18, which also played a key role in determining the relative psychiatric health of children. The researchers suggest that the effects of South African apartheid must be addressed to reduce the risk of mental health issues. Kuzawa is the John D. MacArthur Professor of Anthropology.
Low Socioeconomic Status and Responses to Rewards and Losses
In trying to understand the long-term consequences of poverty, researchers have hypothesized that economic scarcity may lead people to seek immediate rewards at the expense of pursuing long-term goals. In the Journal of Cognitive Neuroscience, IPR psychologist Robin Nusslock, IPR health psychologist Greg Miller, and their colleague study this hypothesis using MRI. To conduct the study, 172 adolescents between the ages of 12 to 15 living in the Chicago area attended an initial session with a parent or guardian who completed an interview about their household finances. The participants were 40.1% White, 30.8% Black, and 29.1% Hispanic. The participants underwent an MRI while performing a passive avoidance task. The adolescents completed 24 trials, choosing to press a button or not press a button when presented with four objects that would allow them to earn or lose money. The researchers find that participants with a lower income-to-poverty (IPR) ratio had worse performance on the passive avoidance task and were less likely to distinguish between reward and loss information. Their analyses identified several brain regions, including attention networks, the parietal cortex, and the ventromedial prefrontal cortex, whose functions contributed to these variations in performance. These findings support the hypothesis that variations in distinguishing between long-term rewards and small, immediate rewards may be a link between poverty and life outcomes. Future research should include longitudinal studies looking at the developmental implications of poverty and how economic interventions may change the brain’s ability to process rewards. Miller is Louis W. Menk Professor of Psychology.
How Childhood Adversity Is Linked with Health Among Potential Parents
Is childhood adversity linked with health risks during pregnancy and childbirth? In Women’s Health Issues, IPR social demographer IPR social demographer Christine Percheski, community health scholar and IPR associate Joe Feinglass, and their colleagues examine the connection between adverse childhood experiences (ACEs) and health conditions that could increase pregnancy and birth complications. ACEs include childhood abuse, exposure to family violence, parental incarceration, and other traumatic experiences. The researchers analyzed ACEs and health histories of thousands of women and men aged 18–39, using survey data from the 2019 Behavioral Risk Factor Surveillance System. They show that women had higher overall ACE scores than men, largely driven by reported sexual abuse. Almost one in four young women reported experiencing four or more ACEs. After accounting for demographic characteristics, young women with four or more ACEs were more likely to be obese, have high blood pressure, and develop diabetes than young women with no ACEs. They were also almost four times as likely to report a history of depression and more than twice as likely to report fair or poor health. The findings suggest a need for a trauma-informed approach to supportive services for mothers and mothers-to-be with ACEs, as well as the need for ‘social infrastructure’ policies that can disrupt the intergenerational transmission of childhood adversity.
Evictions Rates and Adverse Pregnancy Outcomes
Housing instability, especially eviction, can have a negative impact on pregnancy outcomes due to financial, social, and emotional stress. Former IPR post-doctoral fellow Alexa Freedman, IPR health psychologist Greg Miller, professor of obstetrics and gynecology and IPR associate Ann Borders, and their colleagues investigate the connection between neighborhood eviction rates and adverse pregnancy outcomes in a study published in the Journal of Epidemiology and Community Health. The researchers looked at delivery records from 76,938 single births between March 2008 and March 2018 at a Chicago hospital. They used the addresses of individuals to identify neighborhoods, and determined the eviction rates of those neighborhoods using data from Princeton University’s Eviction Lab. The study finds that mothers who lived in neighborhoods with the highest eviction rates were 1.17 times as likely to deliver their babies pre-term and were 1.13 times more likely to deliver a baby with low birth weight compared to those living in neighborhoods with the lowest eviction rates. These results suggest that mothers living in neighborhoods with higher eviction rates are more likely to deliver pre-term. The connection was strongest for individuals with a lower median household income. The researchers argue that it is important to be aware of the connection between eviction rates and pregnancy outcomes in order to inform policy that could improve tenant protections and living conditions in low-income areas. Miller is the Louis W. Menk Professor of Psychology.
Pre-Pregnancy Maternal Mental Health Impact on Children
What impact do pre-pregnancy posttraumatic stress disorder (PTSD) and symptoms of depression among mothers have on the cortisol levels of their young children? Cortisol levels are indicative of stress, and flatter daily cortisol slopes point to adverse mental, physical, and behavioral outcomes for children. In Developmental Psychobiology, IPR developmental psychologist Emma Adam and her colleagues study 85 mother-child pairs participating in research of the Community Child Health Network (CCHN). Before becoming pregnant, women rated their levels of stress and mental health using the PTSD Checklist–Civilian Version, the Perceived Stress Scale, and Postnatal Depression Scale. Then, their children provided saliva samples at the ages of four and five years, which were used to measure cortisol levels three times across the day. The study found that PTSD symptoms in mothers were significantly associated with cortisol levels in their children that were flatter than normal, a pattern which is associated with poor mental and physical outcomes. However, mothers’ pre-pregnancy symptoms of depression and stress did not have an apparent effect on the cortisol levels of their children. Additionally, cortisol awakening responses (CARs) were tested for in children, but were found to have no correlation with pre-pregnancy mental health for mothers. Based on these findings, the researchers suggest women be screened for PTSD allowing for treatment prior to the start of pregnancy to improve maternal and child mental health. Adam is Edwina S. Tarry Professor of Human Development and Social Policy.
The Association Between Childhood Abuse and Cardiovascular Risk
Experiences early in life such as childhood abuse can potentially lead to increased cardiovascular disease risk factors in adulthood. In the Journal of the American Heart Association, pediatrician and IPR associate Nia Heard-Garris and her colleagues examine the association between exposure to abuse in childhood and four major risk factors for heart disease, including obesity, type 2 diabetes, high blood pressure, and hyperlipidemia, or high cholesterol and other fats in the blood, and whether growing up in a nurturing household affects the relationship. The researchers explored data from the ongoing Coronary Artery Risk Development in Young Adults (CARDIA) study, which follows over 5,000 Black and White adults from four cities who were recruited from 1985–86. Participants, who were aged 33–45, completed a questionnaire about their exposure to physical or psychological abuse and their home environment as a child, which aimed to compare associations between abuse, nurturing relationships, household organization and cardiovascular disease risk factors. The results showed that White men who experienced occasional or frequent childhood abuse had a higher risk of developing type 2 diabetes than those who experienced no abuse. For White men and women, the risk for hyperlipidemia was low for those in a non-abusive household. However, the risk was higher for White women in dysfunctional or abusive households. The patterns remain similar for Black men: Those who experienced occasional or frequent abuse had a lower risk of hyperlipidemia if they lived in a well-managed household. Among differing race, gender, and household organization, abuse in childhood was not associated with an increased risk of other cardiovascular disease factors, such as obesity and hypertension. These results suggest that there is a connection between childhood abuse and cardiovascular risk factors that differs by race, gender, and household organization. More research is necessary to better understand these differences.