Oct. 1, 2007 -- The odds of developing Alzheimer's disease may be better for people who consider themselves highly conscientious.
So say researchers including Robert Wilson, PhD, of Chicago's Rush University.
Scientists don't know exactly what causes Alzheimer's disease, which is the most common form of dementia in older adults.
But conscientiousness deserves more attention from Alzheimer's researchers, Wilson's team notes.
Wilson and colleagues studied nearly 1,000 older U.S. Catholic nuns, priests, and brothers from 1994 to 2006.
In 1994, none of the participants had dementia. They completed questionnaires about their personality, medical history, physical activity, cognitive activities (such as reading a newspaper), and other factors.
In the personality survey, participants rated how much they agreed or disagreed with statements about their self-discipline, scruples, and sense of purpose, such as "I am a productive person who always gets the job done."
Based on the survey results, Wilson's team calculated each participant's conscientiousness score. Higher scores indicate higher levels of self-reported conscientiousness.
Participants' conscientiousness scores ranged from a low of 11 to a high of 47 (average score: 34). Those scores are normal in the general public, according to Wilson's team.
Conscience and Alzheimer's Disease
During the 12-year study, participants got annual checkups and took tests of their cognitive skills, including memory.
Participants with high conscientiousness scores were less likely to develop Alzheimer's disease during the study, compared with those with low conscientiousness scores.
That result held when the researchers considered participants' age, physical activity, mental activity (such as reading newspapers), personality, and other factors.
Highly conscientious participants were also less likely than the least conscientious participants to develop milder cognitive problems (such as memory glitches) that may lead to Alzheimer's.
Wilson's team performed autopsies on most of the participants who died during the study. Those autopsies showed no link between participants' conscientiousness scores at the study's start and their chances of having brain plaque or tangles when they died.
Wilson and colleagues call for more research to see if the findings apply to other groups of people and how conscientiousness might help save the brain.