A study involving 6797 participants,  30% women; age range from 40 to 77 years who were followed from 1989 to 2006. Structural and functional social support was measured during follow-up.  Mental and physical health was measured afterwards, during five consecutive follow-up phases.

Social Support and Health

Social support is associated with better health. However, only a limited number of studies have examined the association of social support with health from the adult life course perspective and whether this association is bidirectional.

This study found social support predicted better mental health, and certain functional aspects of social support, such as higher practical support and higher levels of negative aspects in social relationships, predicted poorer physical health. The association between negative aspects of close relationships and physical health was found to strengthen over the adult life course. In women, the association between marital status and mental health weakened until the age of approximately 60 years. Better mental and physical health was associated with higher future social support.

The researchers concluded the strength of the association between social support and health may vary over the adult life course. The association with health seems to be helpful and harmful..

Do Stressful Relationships Impact Cognitive Functioning?

The extent to which social relationships influence cognitive aging is unclear. In this study, we investigated the association of midlife quality of close relationships with subsequent cognitive decline. This study involved 5,873; ages 45–69 years at first cognitive assessment.  They underwent executive function and memory tests 3 times over a period of 10 years (1997–1999 to 2007–2009). Midlife negative and positive aspects of close relationships were assessed twice using the Close Persons Questionnaire during the 8 years preceding cognitive assessment.

Negative aspects of close relationships, were associated with accelerated cognitive aging. Participants in the top third of reported negative aspects of close relationships experienced a faster 10-year change in executive function, than those in the bottom third, which was comparable with 1 extra year of cognitive decline for participants aged 60 years after adjustment for sociodemographic and health status. This study highlights the importance of differentiating aspects of social relationships to evaluate their unique associations with cognitive aging.

Having close personal relationships in middle age that cause stress, problems or worries, may contribute to a decline in thinking ability in older age, according to a new study.

“Any relationship involves both positive and negative exchanges, especially those close relationships that are most likely to evoke ambivalent sentiments,” said lead author Jing Liao of University College London.

“Negative aspects of close relationships refer to unpleasant social exchanges when the recipient finds the relationship ineffective, intrusive or over-controlling,” Liao told Reuters Health by email.

People who reported the most negative aspects of close relationships were also more likely to have symptoms of depression and diabetes than others, according to the results published in the American Journal of Epidemiology.

There is evidence that, in general, those with a partner or those who are less socially isolated report better quality of life and live longer, Liao said.

But healthy people are more likely to have a partner and be more socially engaged, she noted.

“Previous studies, including some of those I have conducted with my colleagues on the Midlife in the United States study, have found that close relationships that involve strain and conflict are associated with poorer executive functioning,” said Margie E. Lachman, director of the Lifespan Initiative on Healthy Aging and Lifespan Lab at Brandeis University in Waltham, Massachusetts.

“This study, which followed the same people over time, was able to confirm that experiencing social strain and stress in close relationships has an impact on cognitive declines,” Lachman, who was not part of the new study, told Reuters Health by email.

Negative aspects of relationships appear to result in cognitive declines, rather than the other way around, she said.

“Further work is needed, however, to see to what extent declines in cognitive functioning might lead to increases in actual negative interactions in close relationships, rather than just describing the relationship as characterized by lack of support and causing stress,” Lachman said.

Better Support, Less Cognitive Decline

The study participants were likely better supported and experienced less cognitive decline than the general population, so the association Liao’s group found may be even stronger for other groups, Liao noted.

The elderly should be encouraged to foster protective relationships, she added.

“Interventions should be targeted at how to reduce negative interactions and alleviate adverse psychological reactions,” potentially by minimizing or resolving conflicts and enhancing the ability to cope, Liao said.