Social isolation linked to poorer mental health

A new study from researchers at the Children's Hospital of Philadelphia (CHOP) shows that the cumulative "wear and tear" of the body, known as allostatic load (AL), can be measured in early adolescence, and that childhood adversity correlates with increased stress and mental health problems in adolescence. The study was published today in the journal Nature Mental Health.

Since the start of the COVID-19 pandemic, children and adolescents are facing increasing mental health challenges. CHOP researchers, driven by a strong commitment to addressing the children's mental health crisis, sought to quantify how the exposome, an environmental exposure, "gets under the skin" and affects physiological systems and mental health, and how differences in the exposome may explain health disparities. The authors also explored the gene-environment mechanisms leading to AL to better understand how stress affects physical and mental health, which may improve prevention and intervention strategies.

"The conventional wisdom is that if you are constantly exposed to stress, your body will pay a price, but that happens over time," said Dr. Ran Barzilai, a psychiatrist at the Center for Youth Suicide Prevention, Intervention and Research at CHOP and lead author of the study. "Our data shows that, although less developed, we can quantify AL in adolescents as early as age 12 and link it to childhood disadvantage and inequality."

In the study, led by Dr. Kevin Hoffman, a child and adolescent psychiatrist at CHOP, the team analyzed data from more than 5,000 diverse adolescents with an average age of 12 years from the longitudinal Adolescent Brain Cognitive Development Study. They calculated latent AL using body mass index, waist circumference, blood pressure, blood glycosylated hemoglobin, blood cholesterol, and salivary levels of the hormone dehydroepiandrosterone (DHEA).

Children's exposure risks were determined by analyzing their environment up to age 11 years through lifestyle factors such as diet, exposure to violence, poverty and pollutants. Genetic risk has been assessed using polygenic risk scores for metabolic problems such as type 2 diabetes (T2D) and psychiatric conditions such as major depressive disorder (MDD).

Using linear mixed-effects models, the researchers assessed the interaction between exposome and polygenic risks and their impact on AL. Overall, they found that the association between childhood environmental exposures and adolescent AL was stronger in people at higher genetic risk for T2D and MDD. The study also found that environmental factors such as childhood adversity, including violence, family dysfunction and poverty, increased AL, which in turn influenced adolescent mental health.

"These results extend the existing literature suggesting a mediating role of AL from childhood adversity to adult mental health and support the hypothesis that AL may be a mechanism contributing to health disparities," Barzilai added. "Importantly, we show evidence of disparities in AL early in life, long before the expected onset of many chronic medical conditions."

For example, non-German white youth had significantly lower AL compared to Hispanic and non-German black youth. Childhood environmental stresses, such as daily challenges in the home and community, were associated with higher AL in adolescence.

Given the serious health disparities in America, the researchers hope these findings will stimulate more research in diverse populations where AL measurements can improve understanding of disparities in childhood health outcomes and related disparities.

“The future of mental health is precision medicine, which allows for a comprehensive understanding of how individual and structural environments, as well as genes, contribute to early health outcomes, both physical and mental,” Barzilai said.

Source: Medical Xpress