Utilizing her interdisciplinary experience in social science and epidemiology, Ping Chen, PhD, specializes in conducting research focusing on social, environmental, behavioral, and biological linkages in developmental and life-course health trajectories. This interest led Chen, an advanced research scientist and social science research methodologist at the UNC Frank Porter Graham Child Development Institute (FPG), to collaborate with FPG colleagues on “Polygenic risk, childhood abuse and gene x environment interactions with depression development from middle to late adulthood: A U.S. national life-course study,” which was published in June in Preventive Medicine.

Researchers in preventive medical research are noticing the association between childhood physical abuse and long-term medical consequences, particularly depression. Understanding how genetic and early family factors and their interactions influence the onset and progression of depressive conditions is crucial, especially considering gender disparities in these processes.

This study used longitudinal data to examine how the risk of polygenic depression—influenced by multiple genetic loci—and childhood abuse interact and influence the life-course development of depressive conditions in men and women from middle to late adulthood. This knowledge can lead to the development of effective prevention and intervention strategies.

“Early exposure to abuse has an influence that we see not just during childhood and adolescence but throughout the entire life,” said Chen. “That's why we need to pay attention to prevention medicine.”

“Early exposure to abuse has an influence that we see not just during childhood and adolescence but throughout the entire life,” said Chen. “That's why we need to pay attention to prevention medicine.” In addition to Chen, the research team included epidemiologist Sabrina Zadrozny, PhD, director of FPG’s Data Management and Analysis Core; FPG Senior Research Scientist Ronald Seifer, PhD; and Aysenil Belger, PhD, an FPG faculty fellow and professor of psychiatry at the UNC School of Medicine; and Yi Li, PhD, associate professor of sociology at the University of Macau.

The researchers analyzed data from the U.S. Health and Retirement Study (1992–2020). The 7,512 participants—4,323 females and 3,189 males—were of European ancestry and between ages 51to 90. The team used the predictor measures of polygenic depression scores and childhood physical abuse and outcome measures including the Center for Epidemiologic Studies Depression Scale (CES-D) and clinical depression risk to tease out how the interactive processes between genetic risk and childhood abuse impact the development of depression in individuals. This offers insights into prevention and intervention strategies that can be personally tailored.

Chen and her colleagues used a life course perspective to understand the interaction among gender, genetic factors, and childhood abuse in relation to depression development. In the study, they note that understanding “how depressive conditions evolve over time under the influence of various factors is essential. Yet, there is a dearth of research applying a life course approach to examine the longitudinal association of gene-environment interactions with depression trajectories.”

This study is the first to examine the childhood-abuse-genetic-risk interaction with lifelong depression. The researchers found that higher polygenic scores elevated depressive symptoms and clinical depression risk. Males ages 51 to 90 years experienced worse depression symptoms and clinical risk because of childhood abuse than females. Particularly, males with high genetic risk were more mentally harmed by childhood abuse.

The researchers found that the “interaction between childhood abuse and genetic factors significantly shaped lifelong depression trajectories in males, while the negative impact of abusive parenting remained constant regardless of polygenic depression risk among females. Individualized prevention and intervention strategies could be crucial in mitigating lifelong depression development, especially for high-genetic-risk males with a history of childhood physical abuse.”

“This is a new contribution to our understanding of gender differences because previously we thought that females had higher depression levels across the life course,” said Chen. “But we found that physical abuse has a more detrimental impact on males than on females, especially among males with high genetic risk for depression.”

Chen says that the main takeaway of this study is the pattern of gender differences. “This is a new contribution to our understanding of gender differences because previously, we thought that females had higher depression levels across the life course,” she said. “But we found that physical abuse has a more detrimental impact on males than on females, especially among males with high genetic risk for depression.”

She hopes that this study leads clinicians and health scientists to notice the gender differences as well as the multiple factors—including genetics and early childhood abuse—so that when they treat patients, they offer individualized prevention and intervention.

While she focused on physical abuse in this paper, Chen plans in the coming years to use longitudinal studies to investigate how early-to-later-life social, environmental and psychosocial factors and their interaction with genetic and biological factors shape lifelong health and social development. In this way, Chen also hopes to extend the focus to protective factors to better understand how they promote more positive development across the life course, from young to old age.