Virginia Commonwealth University researchers have found that women who feel more loved and supported by their friends, relatives and children are less at risk for major depression than men, suggesting important gender differences in the pathways leading to depression.
In the February issue of the American Journal of Psychiatry, the VCU researchers report that among approximately 1,000 adult, opposite-sex, fraternal twin pairs, the female twins reported significantly higher levels of global social support than their twin brothers. The women were more sensitive than the men to the depressongenic effects of low levels of social support, particularly from the co-twin, other relatives, parents and spouses.
“In women, social support was a robust predictor of risk for depression," said Kenneth S. Kendler, M.D., a professor of psychiatry and human genetics in VCU’s School of Medicine and lead author on the study. "Women who saw themselves as more loved and cared for and objectively well integrated in positive social groups were well protected against later episodes of major depression.
“However, among the men we found virtually no effect," he said. "In this large sample, we could find no relationship in men between their levels of social support and their risk for depression.
“These findings suggest that men may be more ‘immune’ or less sensitive to aspects of their social environment with respect to their risk for depression," Kendler said.
Researchers interviewed opposite-sex fraternal twin pairs registered with VCU’s Mid-Atlantic Twin Registry. The first interview was conducted between 1993 and 1996, and the second interview was conducted between 1994 and 1998. At the time of the second interview, subjects were between the ages of 21 and 58 years old.
According to Kendler, studying opposite-sex fraternal twin pairs was ideal because the population included women and men who were conceived at the same time, developed in the same uterus and raised in the same family. Factors that may otherwise differ across women and men were ruled out because this population was examined, Kendler said.
Researchers examined the relationship between baseline levels of social support -- assessed for six key social relationships -- and the general level of social integration. The risk for future episodes of major depression was also assessed.
Kendler, who is also director of the Virginia Institute for Psychiatric and Behavioral Genetics, said these results are consistent with previous literature suggesting that on average, inter-personal relationships are more central to and more valued by women than by men. Women are also more likely to seek emotional support in their social network than are men.
“While the impact of low social support on risk for major depression appears to be less pronounced in men than in women, males may be more sensitive to the adverse health effects of social isolation than are females,” he added.
The VCU Mid-Atlantic Twin Registry is under the direction of Judy Silberg, Ph.D., associate professor of human genetics and psychiatry at VCU. The research was supported by a grant from the National Institutes of Health.
The Virginia Institute for Psychiatric and Behavioral Genetics is a multi-disciplined, integrated research program of VCU’s Departments of Psychiatry and Human Genetics focused on identifying genes and environments that cause psychiatric diseases and behavioral differences. For more, see www.vipbg.vcu.edu.
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