Are certain personality traits developed during adolescence true risk factors for dementia later on in life? This is the question researchers posed, and answered, in a new study published in JAMA Psychiatry.
In order to draw their conclusions, the researchers began by reviewing a 150-item personality inventory that was given to a national sample of teenagers almost 60 years ago.
The 1960 survey assessed character traits such as sociability, calmness, empathy, maturity, conscientiousness, and self-confidence. These traits were then rated using scores ranging from low to high.
For the current study, the scientists compared 82,232 of the original test-takers’ scores to Medicare dementia diagnosis data from 2011 to 2013. They discovered that there is likely a link between personality and increased risk for dementia.
Participants from the 1960 study who identified as having energetic dispositions, high extroversion, calmness, and maturity as adolescents were at a lower risk of dementia years later, the scientists found.
Conversely, the opposite traits (which the researchers named “maladaptive”) were associated with increased dementia risk in older age. The time-lapse between the studies was calculated to be an average of 54 years.
Calmness, in particular, has been linked with lower levels of stress, while maturity reflects an individuals’ degree of conscientiousness.
Both of these traits can correspond to adolescents’ possible future dementia risk: Lower overall stress has a positive implication on stress response pathways associated with dementia, while later-life conscientiousness appears to be protective against dementia as well.
The study’s authors noted that this association did not hold true for individuals with low socioeconomic status (SES). They speculated that this may be due to the stress (ie. financial stress, transportation issues, housing problems, exposure to crime) that is associated with lower SES and these factors’ influence on the stress response pathways implicated in dementia.
Additionally, the authors reminded that it’s possible for persons to display certain personality traits earlier in life and then enter an incipient period of disease in which neuroticism increases and conscientiousness declines, creating unexpected higher dementia risk.
“The study was not set up to discern a causal link,” the lead author, Benjamin P. Chapman, an associate professor of psychiatry at the University of Rochester told the New York Times. “Most likely these traits lead to all kinds of other things over 50 years that culminate in a diagnosis of dementia.”
Essentially, it’s important to take the researchers’ findings with a grain of salt as their conclusions are suggestive and strong conclusions relating to causation cannot be drawn with certainty.