It’s often said that Alzheimer’s disease and other forms of dementia significantly influence behavior and personality. But new research suggests that certain personality traits increase the risk of developing Alzheimer’s.

In fact, researchers from Florida State University and the National Institute on Aging found that personality traits may not develop as a result of Alzheimer’s disease, but are actually present before its onset.

The study followed 2,046 healthy older adults for an average of 12 years, and some for as long as 36 years. Throughout the study, slightly more than 5% of participants developed mild cognitive impairment and 12.5% developed dementia (9.5% of that dementia percentage being Alzheimer’s disease).

Over the course of the research, participants filled out personality assessments on five personality traits:

– Agreeableness

– Conscientiousness

– Extraversion

– Neuroticism

– Openness

Those who scored higher in the neuroticism segment and lower in the agreeableness, conscientiousness and extraversion sections went on to develop Alzheimer’s, according to the research. In addition, there was no change, as those personality traits were apparent from the beginning of the study. The same was true of the dementia and mild cognitive impairment groups.

“Because changes in behavior and personality are one criterion for diagnosing dementia, it is important to realize that it may not be a reliable factor in determining an accurate diagnosis,” the report noted.

Previous studies support these results. One such study from 2014 attested that women categorized as introverts and highly neurotic were more likely to develop Alzheimer’s than the other women involved in the research.

Despite these findings, they don’t necessarily tell the whole story.

“Observational studies like this can be important for picking out health trends, but this type of research is not able to tell us about cause and effect,” said Dr. Simon Ridley, head of research at Alzheimer’s Research UK at the time of the 2014 study. “[M]ore research is needed to understand…the impact of some of the personality traits highlighted here.”