A new study shows that people who are socially active and not easily stressed may be less likely to develop dementia. The research is published in the January 20, 2009, print issue of Neurology, the medical journal of the American Academy of Neurology.

The study involves 506 older people who did not have dementia when first examined. The group was given questionnaires about their personality traits and lifestyle. The personality questions identified people with different degrees of neuroticism, a term meaning easily distressed. The questions also measured extraversion, or openness to talking to people. Those who were not easily distressed were calm and self-satisfied, whereas people who were easily distressed were emotionally unstable, negative and nervous. Outgoing people scored high on the extraversion scale and were socially active and optimistic compared to people with low extraversion who were reserved and introspective.

The lifestyle questionnaire determined how often each person regularly participated in leisure or organizational activities and the richness of their social network. Participants were followed for six years. During that time, 144 developed dementia.

The study found that people who were not socially active but calm and relaxed had a 50 percent lower risk of developing dementia compared with people who were isolated and prone to distress. The dementia risk was also 50 percent lower for people who were outgoing and calm compared to those who were outgoing and prone to distress.

"In the past, studies have shown that chronic distress can affect parts of the brain, such as the hippocampus, possibly leading to dementia, but our findings suggest that having a calm and outgoing personality in combination with a socially active lifestyle may decrease the risk of developing dementia even further," says study author Hui-Xin Wang, PhD, with the Karolinska Institute in Stockholm, Sweden.

"The good news is lifestyle factors can be modified as opposed to genetic factors which cannot be controlled. But these are early results, so how exactly mental attitude influences risk for dementia is not clear," said Wang.

The study was supported by the Swedish Council for Working Life and Social Research, the Alzheimer Foundation Sweden, the Swedish Brain Power, Swedish Research Council, Gamla Tjanarinnor Foundation, Fredrik and Ingrid Thurings Foundation, the Foundation for Geriatric Diseases and Loo and Hans Osterman Foundation for Geriatric Research at Karolinska Institute, and the Center for Health Care Science at Karolinska Institute.