The Interplay of Supportive Environment and Stress Genetics

The study employs a polygenic risk score, which is based on decades of research into which minor differences in specific genes are associated with depression risk.

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In comparison to those in the study who had low depression polygenic risk scores, doctors and widows with higher risk scores had greater rates of depression after losing social support but also reduced rates of depression when they gained social support during stressful periods.

A University of Michigan (U-M), team’s study, published in the American Journal of Psychiatry, suggests that more should be done to focus social assistance on individuals who can benefit the most.

The Link Between Genes, Stress, and Social Connection

“Our data show wide variability in the level of social support individuals received during these stressful times and how it changed over time,” said first author Jennifer Cleary, M.S., a psychology doctoral student at U-M who is doing her research with senior author Srijan Sen, M.D., Ph.D., of the U-M Medical School. “We hope these findings, which incorporate genetic risk scores as well as measures of social support and depressive symptoms, illuminate gene-environment interactions and specifically the importance of social connection in depression risk.”

Sen, the head of the Eisenberg Family Depression Center and a professor of psychiatry and neuroscience, says that while genetic research uncovers more of the DNA variants associated with depression vulnerability, understanding how that variation leads to depression is critical.

“Further understanding the different genetic profiles associated with sensitivity to loss of social support, insufficient sleep, excessive work stress, and other risk factors could help us develop personalized guidance for depression prevention,” he said. “In the meantime, these findings reaffirm how important social connections, social support, and individual sensitivity to the social environment are as factors in well-being and preventing depression.”

Different Populations but Similar Patterns

The new study made use of data from two long-term studies that collected genetic, mood, environment, and other information from communities of participants.

Sen oversees the Intern Health Study, which enrolls first-year medical residents (commonly known as interns) from across the United States and beyond.

The other study is the Health and Retirement Study, which is housed at the University of Michigan Institute for Social Research and is supported by the National Institute on Aging.

The new paper’s data came from 1,011 interns training at hospitals around the country, nearly half of whom were female, and from 435 recently widowed people, 71% of whom have women, who had data from surveys performed before and after their spouses died.

As Sen and his colleagues have previously demonstrated, depression symptoms among interns grew considerably (126%) throughout the stressful year of training that includes lengthy and unpredictable work hours, sometimes in places apart from friends and family.

Depressive symptoms increased by 34% in widows and widowers compared to pre-widowhood levels. These findings are consistent with a previous study suggesting that the loss of a spouse can be one of the most stressful events in a person’s life, according to Cleary.

A Crossover Effect

The depression symptom data were then combined with each person’s polygenic risk score for depression as well as their replies to questions about ties with friends, family, and other social supporters.

The majority of the interns lost social support from their pre-internship days, which aligns with the normal experience of leaving medical school and moving to a new workplace where they may not know anyone.

Interns with the greatest polygenic risk scores who also lost social support had the highest scores on depressive symptom measures later in the stressful intern year.

Those with the same high level of genetic risk who received social support, on the other hand, had much-reduced depression symptoms. Regardless of social support, it was lower than even their contemporaries with minimal genetic risk. The researchers refer to this phenomenon as a ‘crossover effect.’

Unlike the interns, some bereaved people reported an increase in social support following the death of their spouse, maybe because friends and family reached out to offer assistance or just a listening ear.

However, the crossover effect was seen in them as well. Widows with a high hereditary risk for depression who received social assistance experienced a substantially lesser rise in depressive symptoms than their contemporaries with a similar genetic risk who did not receive social assistance after the death of a spouse.

Some widows lost social support or did not see a shift in support, and their depressive symptoms did not improve. Cleary comments that future research should consider this group’s history in light of any caregiving they may have done for a spouse with a long-term illness.

The team also hopes that additional researchers will look into how genetic risk, stress, and social support interact in different groups.

Meanwhile, Cleary and Sen advise anyone going through difficult times, or witnessing a friend or relative go through difficult times, to seek out and preserve or strengthen social bonds.

They point out that doing so can assist both the individual under stress and the person reaching out to them.

Reducing the person’s persistent stress, whether at work, school, after a personal loss, or in family situations, might be crucial.

Individual and group therapy is an important alternative for persons who have developed depression or other mental health difficulties, even though the study did not investigate the role of professional mental health care.

Social support appears to reduce hereditary and environmental vulnerabilities to mental illness, presumably through impacts on other psychosocial factors such as encouraging appropriate coping skills as well as effects on numerous neurobiological aspects.

Psychiatric researchers will need to conceive, test, and implement successful interventions geared specifically at boosting social support for psychiatrically ill or at-risk groups. This is a significant difficulty for the field.

Reference :

1. Polygenic Risk and Social Support in Predicting Depression Under Stress – (https:ajp.psychiatryonline.org/doi/abs/10.1176/appi.ajp.21111100)

Source: Medindia