There are also aspects of mental wellbeing which are thought to influence the development of Alzheimer’s. These include stress, mental activity and head trauma.    
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  Stress is being investigated as a possible risk factor. In stressful events large amounts of hormones are produced, such as adrenaline and cortisol. The hippocampus is the main area of the brain where cortisol and other steroid hormones interact. (As mentioned earlier in “A Tale of Two Cerebral Deposits”, the hippocampus is the area of the brain which undergoes the most significant amount of shrinkage during Alzheimer’s disease.) The concentration of cortisol largely determines its effect. A deficit of the hormone affects nerve development, whereas overproduction leads to death in the cells of the hippocampus. A 35 year long Swedish study investigated the effects of stress on 1500 women. The results showed that stressful events in the lives of the subjects increased their risk of dementia by 65%. Another study using mouse models showed that stress exacerbates the formation of tau tangles. The mice were put under repeated experiences of emotional stress. The results showed a significant increase in tau tangles, primarily in the hippocampus. With further research into the effects of stress, scientists hope to gain a better understanding of the mechanisms of Alzheimer’s and the extent to which stress contributes to its development.

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Alzheimer’s sufferers are widely advised to keep mentally active in order to slow their cognitive deterioration. But this advice is often challenged by Alzheimer’s research organisations. In the prevention of Alzheimer’s, the NHS website advises people to “stay mentally active, for example, by reading, writing or taking an adult education course”. However, this view is being cautioned upon by Alzheimer’s research organisations. Following the release of a study in 2009 which suggested the benefits of mental stimulation, the Alzheimer’s Society commented; “more research, where people are followed up over time, is needed to understand whether these sorts of activities can reduce the risk of dementia”. The National Institute of Health held a conference called “State-of-the-Science” wherein a panel asserted that there was “insufficient” evidence for this claim.

Although there has been little evidence to suggest that mental stimulation does have intervening effects, there have been studies to show a correlation between years of education and susceptibility. The relationship between neuropathology and education remains uncertain. However one investigation analysed 872 brains, 56% of which were from donors who had suffered from dementia. They found that increased years of education did not prevent dementia, but it did reduce the risk. However, this study also suggests that poor educational experience is associated with lower status. Low status is considered as a risk factor for cardiovascular disease.

  It appears that more extensive studies need to be done into the effects of mental health on the development of Alzheimer’s disease. In comparison to the effects of cardiovascular disease and insulin, it is more difficult to determine the effects of mental health.
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There are many environmental risk factors that contribute to the development of Alzheimer’s. Their effects can help us to understand how the disease is caused. We now have several different potential drug targets, as well as knowledge of preventative measures people can take to attempt to decrease their risk. However, these preventative measures are not proven to have any definitive effect. Therefore it stands to reason that genetics must also play a significant part.

References
Ahramjian, L., 2010., Independent Panel Finds Insufficient Evidence to Support Preventive Measures for Alzheimer's Disease, NIH News [online] Available at:< http://www.nih.gov/news/health/apr2010/od-28.htm> [Accessed 15 September 2012]

Alzheimer’s Society, 2009. Research into impact of mental activity on memory loss [online] Available at: <http://alzheimers.org.uk/site/scripts/news_article.php?newsID=423> [Accessed 15 September 2012]

Brayne, C. et al, 2010. Education, the brain and dementia: neuroprotection or compensation? Brain [online] Vol.133. Issue 8. Pp2210-2216 Available at: <http://brain.oxfordjournals.org/content/133/8/2210.long#cited-by> [Accessed 10 September 2012]

LaFee, 2012. Chronic Stress Spawns Protein Aggregates Linked to Alzheimer’s [online] Available at: <http://ucsdnews.ucsd.edu/pressreleases/chronic_stress_spawns_protein_aggregates_linked_to_alzheimers/> [Accessed 10 September 2012]

NHS choices, 2012. Alzheimer’s Disease – Prevention [online] Available at: <http://www.nhs.uk/Conditions/Alzheimers-disease/Pages/Prevention.aspx> [Accessed 10 September 2012]

Roberts, M. 2012. Role of stress in dementia investigated, BBC News [online] Available at: <http://www.bbc.co.uk/news/health-18577326> [Accessed July 18 2012]

Rose, S, 2003. The Making of Memory; From Molecules to Mind, Revised Edition, Great Britain : Vintage
 


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