This fascinating short piece in the NY Times http://www.nytimes.com/2010/07/20/health/research/20risk.html?_r=1&ref=science adds insight into the relationship between the brain and the mind.
In brief the article points to the higher incidence in subsequent dementia in those who were depressed throughout large periods in their early lives.
Some could argue that both depression and dementia are diseases of the physical brain. There are clearly examples of brain-related depressions to be sure. But what is implied by this article is that the persistent mood state of depression can lead to the structural changes in the brain characteristic of dementia.
This is consistent with other examples in which the active choices of our minds induce physical changes in the brain. Although this concept may seem self-evident to some, it is not embraced in general by neuroscientists. Many believe that our thoughts and feelings are based primarily upon the structure of the neurons, synapses and interconnections within our physical brain. It is argued that our thoughts and feelings are the consequence not cause of these cerebral structures and interconnections.
It raises the centuries old philosophical issue of the mind/brain relationship.
Evidence from long time meditators clearly demonstrates physical and physiologic changes in their brains. It is highly unlikely that they were born with such neurocognitive brain patterns.
So we are left with the lesson that what we think, how we feel, how we interpret the events in our lives may ultimately lead to issues of healing or suffering.
No one pretends that choosing an optimistic attitude on life is easy or always doable. We all experience mental and emotional suffering but some of us successfully make the courageous effort to move past them and accept life on its own terms. They seek and do find serenity.
Multiple studies do clearly demonstrate that those who can view life with a glass half-full, live a healthier life than their half-empty colleagues and now, it seems, are less likely to suffer from dementia as well.