This study  shows yet again how complex the class of congnitive disorders is.

Specifically, this study is about dementia and Alzheimer’s, the ones that scare the daylights out of people.

- What many people may not know is that scientists have identified a genetic component in cognitive impairment diseases.

- What many people do know is that rich social networks, including marriage at the top of the list, appear to offer protective benefits to people, especially those who have a genetic-related higher risk for dementia diseases.

- What does this study tell us? It shows us much more about the importance of the relationship between genetic risk and social risk.

For people who carry the gene difference (apolipoprotein E e4 allele), one which increases their individual risk, the highest risk for Alzheimer’s disease was found among individuals who lost a partner at mid-life ( a mean of 50.4 years) and who remained widowed or divorced at follow-up (65-79 years) had the highest increased risk.

Being widowed or divorced is not a choice many make on their own.

Those people who have rich social networks and no genetic risk are owed as much information as possible about lowering their risks through activities they can control.

People who have both genetic and social risk are owed top priority from researchers, to examine all the ways that they can reduce their risks in a social way. This is called for in the conclusions section of this study.

This is a free, full article. For families who have had members suffer from dementia or Alzheimer’s, you can read the whole article online. It is scientific research, so most readers will find parts of it too much scientifically, but you should try to use it to understand what you can.

British Medical Journal

Results “People cohabiting with a partner in mid-life (mean age 50.4) were less likely than all other categories (single, separated, or widowed) to show cognitive impairment later in life at ages 65-79. Those widowed or divorced in mid-life and still so at follow-up had three times the risk compared with married or cohabiting people. Those widowed both at mid-life and later life had an odds ratio of 7.67 (1.6 to 40.0) for Alzheimer’s disease compared with married or cohabiting people. The highest increased risk for Alzheimer’s disease was in carriers of the apolipoprotein E e4 allele who lost their partner before mid-life and were still widowed or divorced at follow-up. The progressive entering of several adjustment variables from mid-life did not alter these associations.

Conclusions Living in a relationship with a partner might imply cognitive and social challenges that have a protective effect against cognitive impairment later in life, consistent with the brain reserve hypothesis. The specific increased risk for widowed and divorced people compared with single people indicates that other factors are needed to explain parts of the results. A sociogenetic disease model might explain the dramatic increase in risk of Alzheimer’s disease for widowed apolipoprotein E e4 carriers.

Citation: British Medical Journal, 2009;339:b2462