Childhood trauma predicts higher risk of combined mental and physical illness in later life

Trauma experienced during childhood is associated with a substantially higher risk of developing overlapping physical and mental illnesses in later life. Researchers analyzing a large group of aging adults in China found that a history of severe early adversity elevated the chances of suffering from simultaneous depression and chronic diseases. The findings were recently published in the Journal of Affective Disorders.

Health care professionals are paying increasing attention to a diagnostic category known as physical and psychological multimorbidity. This term describes the simultaneous presence of at least one chronic physical illness alongside a distinct psychological condition. An example would be an aging adult managing chronic arthritis while also experiencing clinical depression. Individuals living with both types of ailments tend to experience worse overall health outcomes than those facing a single condition.

The burden of managing these combined illnesses goes beyond the sum of their individual parts. Patients with overlapping physical and mental health issues generally show reduced adherence to medical treatments. They also face higher daily care costs, a steeper risk of physical disability, and higher mortality rates. Because these overlapping illnesses create such a profound burden on the aging body, scientists urgently want to understand the origins of this vulnerability.

Previous research has repeatedly linked harsh childhood environments with individual disease categories later in life. Surviving abuse, neglect, or severe household dysfunction is known to increase the likelihood of isolated health problems. Unstable early environments can set the stage for everything from heart disease to severe mood disorders well into adulthood. Yet, the vast majority of earlier investigations examined these physical and psychological outcomes completely separately.

In addition to measuring isolated diseases, most prior studies relied heavily on cross-sectional data. A cross-sectional approach captures a single snapshot in time rather than tracking people as they age. To build a more dynamic and detailed picture, researchers at Peking University set out to investigate how early childhood trauma might predict the ongoing onset of combined mind and body illnesses. Lead author Xing He and corresponding author Chao Guo guided the investigation, exploring a large population in a middle-income country where such data is rarely analyzed.

The research team utilized data from the China Health and Retirement Longitudinal Study. This initiative is a nationally representative survey tracking the health, social, and economic status of middle-aged and older Chinese adults. The resulting dataset for this specific study included 4,015 participants from a wide variety of rural and urban settings. All participants were at least 45 years old when the baseline survey began in 2011.

The researchers followed the participants’ health records through several biannual survey waves, ending in 2018. To guarantee they were tracking newly developed combined illnesses, the researchers excluded anyone who already had simultaneous physical and psychological conditions at the start of the study. In a 2014 follow-up wave, participants completed a detailed retrospective life history questionnaire. They answered questions regarding 20 different forms of childhood adversity.

These adverse events included instances of physical and emotional abuse, intense neglect, and persistent bullying. The survey also captured non-interpersonal struggles, such as extreme childhood poverty, parental loss, and household substance misuse. Based on the responses, the researchers grouped the participants into three distinct categories.

Those reporting zero adverse childhood experiences formed the first baseline group. People reporting one to three types of trauma made up the low exposure group. Meanwhile, those acknowledging four or more adverse experiences were classified into the high exposure group. More than 85 percent of the participants reported at least one adverse childhood event.

For the health outcomes, the team monitored the eventual onset of both clinical depression and 14 specific chronic physical conditions. The physical ailments ranged from hypertension and diabetes to liver disease and asthma. Participants were classified as having a physical and psychological multimorbidity if they demonstrated clinically relevant depressive symptoms at the exact same time they reported a chronic physical disease.

Over the course of the tracking period, a large portion of the study group developed these overlapping conditions. Specifically, just over 42 percent of the participants developed combined physical and psychological illnesses by 2018. When researchers unpacked the data by childhood adversity levels, a distinct pattern of rising risk emerged.

Adults who experienced one to three adverse childhood events had a 20 percent higher risk of developing overlapping illnesses compared to those who reported trauma-free upbringings. The risk spiked substantially for respondents enduring an excessive amount of early trauma. People reporting four or more adverse childhood experiences faced a 56 percent higher risk of developing a combined physical and psychological illness.

Researchers modeled the specific dosage of trauma to highlight an escalating relationship between the sheer volume of trauma and later health vulnerabilities. Small amounts of childhood adversity corresponded to relatively modest increases in health risks. However, once a person’s trauma score passed four distinct adverse experiences, the upward trajectory of their health risk accelerated rapidly.

The researchers also investigated the stepping stones connecting early trauma to later disease onset. Using a statistical technique called mediation analysis, they looked for intermediate health issues that acted as bridges over the span of a lifetime. They found that developing either a single physical illness or isolated depression in early adulthood often served as an indirect pathway to combined disease in older age.

For individuals with the highest amounts of early trauma, early-onset depression played a particularly strong bridging role. An initial diagnosis of depression frequently paved the way for additional physical conditions as time went on. These findings align with biological theories suggesting that severe childhood stress permanently disrupts the body’s immune regulation and stress hormone pathways.

The data also revealed varied disease patterns between men and women within the aging cohort. Women with trauma histories exhibited a heightened vulnerability to developing combined illnesses compared to men with similar trauma backgrounds. The authors proposed that this pattern might arise from differences in biological stress sensitivity or the cumulative daily pressures of specific gender roles.

While the study tracked adults across an extended timeframe, the authors noted several limitations in their approach. The reliance on retrospective self-reporting for childhood trauma introduces the possibility of recall errors. Participants might forget or intentionally underreport especially difficult early memories, which could alter the calculated trauma scores.

Additionally, the researchers measured physical disease using simple, unweighted counts of clinical conditions. This method fails to account for the varying severity of an illness. Under this metric, a minor physical condition is given the same statistical weight as a highly debilitating disease. The psychological measurement was also entirely restricted to depressive symptoms, leaving out other mental health conditions like chronic anxiety or trauma-related psychiatric disorders.

Excluding participants who already had overlapping conditions at age 45 might have also shifted the ultimate risk estimates. By entirely focusing on cases that developed newly in later adulthood, the researchers potentially omitted people who developed severe joint illnesses early in life. Because of this restriction, the final numbers might actually underestimate the true burden of childhood trauma across the lifespan.

Despite these limitations, the research draws attention to the long tail of childhood experiences, stretching from infancy well into a person’s retirement years. The researchers recommend incorporating trauma screening into routine medical assessments for aging adults. By identifying patients with a history of severe early adversity, primary care providers might be able to offer targeted mental health support before isolated conditions evolve into overlapping diseases.

The study, “The long-term impact of adverse childhood experiences on later-life physical and psychological multimorbidity: A prospective cohort study of middle-aged and older adults in China,” was authored by Xing He, Mingxing Wang, Yushan Du, Ziyi Ye, Ying Yang, and Chao Guo.