September 28, 2017
By Marilynn Larkin
NEW YORK (Reuters Health) – A study has found no evidence of preclinical changes in personality before the onset of mild cognitive impairment or dementia, suggesting that personality traits are likely to be a risk factor for the disorders, according to researchers.
As Dr. Antonio Terracciano of Florida State University in Tallahassee and colleagues note, although changes in behavior and personality are a criterion for a dementia diagnosis, whether such changes begin before the clinical onset of the disease has not been clear.
To investigate, the team analyzed data from 2,046 participants in the Baltimore Longitudinal Study of Aging who had no cognitive impairment at baseline and were followed for up to 36 years (mean, 12 years).
About 45% of participants were women, and the mean age at first assessment was 61 for those without dementia and 72 for those with Alzheimer’s disease, all-cause dementia or mild cognitive impairment.
Personality and clinical evaluations were obtained between 1980 and 2016. The main outcome was change in self-reported personality traits during the preclinical phase of dementia as assessed by the Revised NEO Personality Inventory, which measures neuroticism, extraversion, openness, agreeableness and conscientiousness.
As reported in JAMA Psychiatry, online September 20, during 24,569 person-years of follow-up, 104 people (5.1%) were diagnosed with mild cognitive impairment and 255 (12.5%) with all-cause dementia, including 194 (9.5%) with Alzheimer’s disease.
After adjustment for demographic variables, significant differences (about 0.3 standard deviations) were identified on the intercept of several traits: People who developed dementia scored higher on neuroticism and lower on conscientiousness and extraversion, compared with non-impaired individuals.
However, the researchers uncovered no significant evidence of self-reported changes in personality before onset of mild cognitive impairment or dementia, compared with people who remained unimpaired.
“We found no changes in personality that could be characterized as early signs of the disease,” Dr. Terracciano told Reuters Health.
“This is important because while changes in personality are one of the signs of clinical dementia,” he said by email, “our long-term study shows that these personality changes do not emerge before the onset of mild cognitive impairment or dementia.”
“There is evidence that standard treatments, like psychotherapy or SSRIs, can reduce neuroticism,” he noted. “However, further research is needed to see whether treating neuroticism might in any way help prevent or affect the course of mild cognitive impairment/dementia.”
“This study did not address obsessive compulsive disorder, depression or other mental health issues,” he added. “The literature is mixed on whether those conditions change in the preclinical phase of Alzheimer’s disease.”
Dr. D.P. Devanand, director of geriatric psychiatry at Columbia University Medical Center in New York City, told Reuters Health, “The magnitude of the observed effects (in the study) was small, and this should be considered, i.e., the personality changes were fairly subtle and not dramatic. These findings are consistent with some but not all of the published literature.”
Furthermore, a self-report of personality was administered, rather than eliciting input from an observer such as a family member, he said by email. “Personality is very difficult to assess reliably, and using self-report alone may be insufficient to get a full picture of an individual’s personality.”
“The age of the people who developed Alzheimer’s disease was, on average, 10 years greater than those who did not clinically develop the disease,” Dr. Devanand continued. “The authors acknowledge this difference, but it is a major confound that cannot be resolved statistically in a convincing manner.”
“One option (would have been) to restrict the comparison group to individuals of a similar age - average 70 years - to those who developed Alzheimer’s disease, but this wasn’t done,” he noted.
“Overall, the results have some clinical value in that changes in personality reported by the patient or (a relative) should be considered possible risk factors and not as symptoms that are likely to progress as the other symptoms of the disease develop,” he said.
“However, what we include under personality nowadays, e.g., behavioral changes related to other factors like anxiety and depression and interpersonal conflict, were not assessed well separately in the NEO scale, which focused on concepts such as neuroticism and extraversion that were in vogue at the time that the initial wave of assessments was done several decades ago,” he said.
Other studies that assessed more-current aspects of behavioral change have shown that “these factors do, in fact, become more prominent as the disease begins to manifest clinically,” he concluded.
JAMA Psychiatry 2017.
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