Having a reliable, approachable and understanding relationship with spouse or partner, children and other immediate family members may put older adults at reduced risk of developing dementia, says a study.

Conversely, negative social support characterised by experiences of critical, unreliable and annoying behaviour from spouse or partner, children and other immediate family is linked with increased risk, according to the 10-year follow-up study published in the Journal of Alzheimer's Disease."It is well known that having a rich network of close relationships, including being married and having adult children, is related to a reduced risk of cognitive decline and developing dementia," said one of the study authors Mizanur Khondoker from University of East Anglia in England.

"However, a relationship or social connection that does not work well can be a source of intense interpersonal stress, which may have a negative impact on both physical and mental health of older adults. It is not only the quantity of social connections, but the quality of those connections may be an important factor affecting older people's cognitive health," Khondoker explained.

The study was based on data from the English Longitudinal Study of Ageing (ELSA).The researchers analysed a decade of data that followed 10,055 core participants from ELSA who were dementia-free at the start of the study in 2002-2003.Participants were interviewed every two years during 2004-2012 and incidence of dementia was identified from self-reports by participants or information given by nominated informants.Measures of positive and negative experiences of social support were calculated at baseline (2002) using a set of six items within the 'Health and lifestyle of people aged 50 and over' questionnaire of ELSA.The scale ranged from one to four with higher values indicating more of positive or negative support.An increase of one point in the positive social support score led to up to a 17 per cent reduction in the instantaneous risk of developing dementia, the findings showed.But negative support scores showed stronger effects -- an increase of one point in the negative support score led to up to 31 per cent rise in the risk.