Social support benefits individuals prone to depression under stress

A nurturing social environment turns out to be helpful to individuals who are genetically at greater risk for developing increased depressive symptoms under adverse social conditions, as shown in a study.

The authors examined the effect of social support on the odds of depressive development across the spectrum of genomic risk in two cohorts that experienced substantial life stress: 1,011 first-year training physicians (interns) in the Intern Health Study (IHS) and 435 recently widowed participants from the Health and Retirement Study (HRS).

Questionnaires were administered before and after the life stressor to assess the participants’ depressive symptoms and social support. The authors then calculated polygenic risk scores (PRS) for major depressive disorder for both groups.

Depressive symptom scores rose by 126 percent and 34 percent after the start of internship in the IHS sample and after widowing in the HRS sample, respectively.

Depression PRS was associated with change in social support in the prediction of depressive symptoms in both IHS sample (incidence rate ratio [IRR], 0.96, 95 percent confidence interval [CI], 0.93‒0.98) and the HRS sample (IRR, 0.78, 95 percent CI, 0.66‒0.92). Specifically, higher depression PRS contributed to greater sensitivity to changes in social support.

Finally, “Johnson-Neyman intervals indicated a crossover effect, with losses and gains in social support moderating the effect of PRS on depressive symptoms. (Johnson-Neyman interval in the IHS sample, −0.02 to 0.71; in the HRS sample, −0.49 to 1.92),” the authors said.