A person's personality as a teen has a greater role in the development of dementia later in life, according to a study, which suggests people who are calm, energetic, and mature during high school are at a lower risk of developing the neurodegenerative disease than those who displayed higher levels of impulsivity.
The results of the study are based on the examination of personality traits of more than 82,000 students in about 1,200 US high schools, who were made to take the personality test then in the 1960s, and more than 50 years later studied for dementia -- an umbrella term for a set of symptoms that affect cognitive function such as memory loss, confusion and changes to personality.
Co-author Kelly Peters, the principal researcher at the American Institutes for Research in Washington, DC, said being calm and mature as a teen was associated with about 10 per cent reduction, and vigour associated with a seven per cent reduction in adult dementia risk.
The study at an average age of 16 assessed students for traits including calmness, vigor, organization, self-confidence, maturity/responsibility, leadership, impulsivity, desire for social interaction, social sensitivity, and artistic and intellectual refinement, and found that more than 2,500 by the age of 70 years around 2011-2013 had developed dementia.
The researcher said there was plenty of evidence that personality changed near the time of a dementia diagnosis, but whether personality actually caused dementia was the bigger question.
She said the study published in JAMA Psychiatry focused on "Is it only that personality can be affected by dementia? Is it just an expression of the disease?" by studying teens who did not later in their lives develop dementia.
Peters said the findings could help policy thinkers develop improved social support systems "to help kids build up protective qualities, but reserved that money seemed to matter as calmness, vigour, and maturity did not appear to protect against adult dementia teenagers who grew up in relatively poor households.
Lead author Benjamin Chapman, an associate professor of psychiatry at the University of Rochester in New York, explained calmness was defined as being stress-free and not neurotic; vigour as being energetic and outgoing; and maturity as being responsible, reliable and conscientious.
Porsteinsson, director of the university's Alzheimer's Disease Care, Research and Education Program, said the average age of an Alzheimer's diagnosis was around the early 80s, and the results could be more productive if repeated in another 10 to 15 years to see what happened to the participants when dementia risk was at peak.
Heather Snyder, vice president of medical science relations at the Alzheimer's Association, said there was not enough evidence at this time to suggest that an intervention strategy for personality type in high school would be effective.