March 2, 2010— -- Patients who maintain a greater sense of purpose in life as they age may have greater protection against Alzheimer's disease, researchers have found.
Those with a purpose had more than a 50 percent reduced risk of the disease, Dr. Patricia A. Boyle of Rush University Medical Center in Chicago and colleagues reported in the March issue of the journal Archives of General Psychiatry.
"The tendency to derive meaning from life's experiences and to possess a sense of intentionality and goal directedness are associated with a substantially reduced risk of Alzheimer's disease and a less rapid rate of cognitive decline in older age," the researchers wrote.
Some data have suggested that psychological factors such as extraversion and neuroticism, as well as experiential factors including social networks, are associated with risk of Alzheimer's disease.
Purpose -- which the researchers define as a "psychological tendency to derive meaning from life's experiences and to possess a sense of intentionality and goal directedness that guides behavior" -- has long been thought to protect against adverse health outcomes. For example, it was recently reported to be associated with longevity, they noted.
But there was little information on the association of purpose with Alzheimer's disease.
So the researchers conducted a study of 951 community-dwelling older patients without dementia who participated in the Rush Memory and Aging Project.
Each had a baseline evaluation about purpose in life, which incorporated a 10-item scale that included agree/don't-agree statements such as "I feel good when I think of what I have done in the past and what I hope to do in the future" and "I enjoy making plans for the future and working them to a reality."
Patients were followed for up to seven years, with an average follow-up of about four years. During that time, 155 patients developed Alzheimer's disease.
The researchers found that those who developed the disease were older and reported lower purpose in life than those who did not.