Researchers associate personality shifts with frontotemporal dementia functional decline

Frontotemporal dementia often results in early changes in personality or behavior before changes in cognitive skills. People with this condition who have lower levels of conscientiousness, a personality trait related to organization, reliability and planning, may be more likely to have problems with their ability to complete everyday activities, according to a study published November 10, 2026, in Neurology^®, the medical journal of the American Academy of Neurology.

The study does not prove that personality changes cause problems with functioning. It only shows an association.

Conscientiousness includes organization, planning, reliability and persistence.

The study involved 111 people with the type of frontotemporal dementia that mainly affects behavior and personality, which is the most common type of frontotemporal dementia. Other types mainly affect language or movement.

The participants were in the early stages of the progressive disease and had an average age of 63.

Family members or caregivers completed questionnaires about the participants' current personality traits and those from about 10 years before they developed the disease. The assessment looked at the main five personality traits of openness, conscientiousness, extraversion, agreeableness and neuroticism.

The family members and caregivers also completed a questionnaire on the participants' ability to manage 10 complex daily activities during the previous month. These included managing finances, shopping and preparing meals.

The researchers found substantial changes in all five personality traits after the disease onset. People had decreased openness, conscientiousness, extraversion and agreeableness and increased neuroticism. Neuroticism is defined as the tendency to experience negative emotions such as anxiety, depression and stress.

People's personality traits after disease onset were associated with their everyday functioning. Current personality traits accounted for approximately 40% of the variation in functional scores. People's personality traits before they developed the disease were not associated with the daily functioning scores.

When researchers looked at individual personality traits, conscientiousness was the only trait independently associated with everyday functioning. People with lower conscientiousness were more likely to have worse scores on everyday functioning.

"Asking family members and giving brief personality assessments may become a useful tool in anticipating people's future challenges with organization, planning and completing their daily tasks," Rankin said. "This could allow for educating caregivers and implementing interventions such as simplifying routines, adding structure to people's tasks and helping people get started on tasks."

A limitation of the study was that caregivers provided information about both personality and everyday functioning, which could lead to inflated associations between the two measures.

The study was supported by the National Institutes of Health and the Larry L. Hillblom Foundation.

Source:

American Academy of Neurology