Summary: Social support during stressful periods can significantly reduce the likelihood that people with genetic susceptibility to depression will develop symptoms.
Source: University of Michigan
Offering support to someone under stress is always valuable. New research indicates that social support may be particularly protective for people whose genetic profile increases their risk of depression.
This study highlights how social connection buffers the development of depressive symptoms, drawing on data from two very different stressed populations: first-year medical residents in an intense training year and older adults who recently lost a spouse.
While social support mattered across both groups, the strongest effects appeared in those with the greatest genetic variation linked to depression risk.
Researchers measured genetic vulnerability using a polygenic risk score (PRS), which aggregates many small genetic variants that prior research has associated with major depressive disorder.
Compared with participants who had low depression PRS, doctors-in-training and recently widowed adults with higher PRS experienced larger increases in depressive symptoms when they lost social support, but markedly lower symptoms when support increased during stressful periods.
The study, published in the American Journal of Psychiatry by a University of Michigan team, suggests targeted efforts to preserve or strengthen social support could be especially beneficial for individuals at higher genetic risk for depression.
Genes, stress and social connection
“Our data show wide variability in the social support people received during stressful transitions and how that support changed over time,” said Jennifer Cleary, M.S., a doctoral student in psychology at the University of Michigan and the study’s first author. She conducted the research with senior author Srijan Sen, M.D., Ph.D., a professor of psychiatry and neuroscience.
Cleary emphasized that combining genetic risk scores with measures of social support and depressive symptoms helps illuminate how genes and environment interact, and underscores the role of social connection in shaping depression risk.
Sen, director of the Eisenberg Family Depression Center, added that as genetic studies identify more DNA variation associated with depression vulnerability, understanding how those variations lead to symptoms is essential.
“Better characterizing which genetic profiles increase sensitivity to loss of social support, insufficient sleep, excessive work stress, or other triggers could lead to personalized prevention strategies,” he said. “Meanwhile, these findings reinforce the importance of social connections and the social environment for mental well-being.”
Different populations, similar patterns
The authors analyzed data from two long-term cohort studies that collect genetic, mood, and environmental information. One was the Intern Health Study, which follows first-year medical residents across the U.S. The other was the Health and Retirement Study, which tracks older adults over time.
The analysis drew on 1,011 interns (nearly half female) and 435 recently widowed participants (71% female) who had survey data from before and after the onset of their respective stressors.
Among interns, depressive symptoms rose dramatically—by 126%—during the demanding intern year, a period characterized by long, irregular hours and frequent relocation away from prior social networks. In the widowed sample, depressive symptoms increased by 34% following spouse loss, consistent with research that identifies bereavement as a major life stressor.
A crossover effect
The team combined each person’s depression PRS with their reported changes in social support and measures of depressive symptoms. Most interns reported losing social support compared with their pre-internship lives, reflecting the common disruption of moving to a new hospital setting.
Interns with the highest PRS who also lost social support showed the largest increases in depressive symptoms. However, interns with similarly high PRS who gained social support during the year had much lower symptom levels—lower even than peers with low genetic risk regardless of support changes. The authors describe this pattern as a “crossover effect.”
Some widowed participants reported increased support after their spouse’s death, as friends and family stepped in. The crossover effect appeared in this group as well: widows and widowers with high genetic risk who gained social support experienced smaller symptom increases than those with high risk who lost support.
The authors note that some widowed participants who lost support or saw no change did not show shifts in depressive symptoms; future research should examine whether caregiving history or other life circumstances explain this stability for certain individuals.
The researchers encourage further studies across diverse populations to confirm how genetic risk, stress, and social support interact to influence depressive outcomes.
In the short term, Cleary and Sen recommend maintaining and strengthening social connections for anyone facing major stress. Reaching out to friends, family, colleagues, or neighbors can benefit both the person under stress and those who offer support. Reducing ongoing stress—at work, school, or in the home—also matters, and professional mental health care, including individual or group therapy, remains an important option for people with depression.
About this genetics and depression research news
Author: Press Office
Source: University of Michigan
Contact: Press Office – University of Michigan
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Original Research: Closed access. “Polygenic Risk and Social Support in Predicting Depression Under Stress” by Jennifer L. Cleary et al., American Journal of Psychiatry
Abstract
Polygenic Risk and Social Support in Predicting Depression Under Stress
Objective:
Despite progress identifying genomic variation linked to major depression, mechanisms by which genetic and environmental factors jointly shape depression risk are not fully understood. One potential mechanism is genomic sensitivity to the social environment. The authors evaluated whether changes in social support influence depressive symptoms differently across levels of genomic risk in two samples experiencing major life stress: 1,011 first-year physicians in the Intern Health Study and 435 recently widowed participants in the Health and Retirement Study.
Methods:
Depressive symptoms and social support were measured with questionnaires administered before and after the stressor for each participant. Polygenic risk scores for major depressive disorder were calculated for both samples and used to assess interactions with social support changes.
Results:
Depressive symptoms rose by 126% after internship start in the IHS sample and by 34% after widowing in the HRS sample. Interaction analyses showed that higher depression PRS was associated with greater sensitivity to changes in social support when predicting depressive symptoms in both samples (IHS: incidence rate ratio [IRR]=0.96, 95% CI=0.93–0.98; HRS: IRR=0.78, 95% CI=0.66–0.92). Johnson-Neyman analyses indicated a crossover effect in both samples, where losses and gains in social support moderated the impact of PRS on symptoms.
Conclusions:
These findings suggest that individuals with higher genomic risk for depression are more sensitive to social environment changes and also derive greater benefit from nurturing social support during adverse conditions. Targeting social support for those at elevated genetic risk may help prevent or reduce depressive symptoms during stressful life events.