Neuroticism, a personality trait associated with emotional instability, appears to interact with other factors to influence cortical thickness the anterior cingulate, a region of the brain linked to anxiety and mood disorders.

The new findings, which appear in Psychiatry Research: Neuroimaging, suggest that age and gender influence the relationship between neuroticism and cortical thickness.

“I was interested in examining the mind-body connection. Specifically, there is still a lot to learn about the relationship between mental health and brain physiology. By examining a personality trait in healthy adults we could see how a lifelong psychological trait relates to physiology,” said study author Melissa Sweeney of Columbia University.

The study of 450 participants between the ages of 19 and 80 used magnetic resonance imaging to examine the relationship between neuroticism and cortical thickness.

The researchers found that both age and gender interacted with neuroticism to predict cortical thickness in the anterior cingulate.

Women high in neuroticism tended to have thinner cortex in the anterior cingulate with increasing age, while men high in neuroticism tended to have thicker cortex in the anterior cingulate with increasing age, compared to those with lower levels of neuroticism.

“The relationship between the personality trait of neuroticism and brain physiology is complex, as we found it is affected by both age and gender. It’s important because neuroticism is the only personality trait associated with psychopathology,” Sweeney explained.

“This was a cross-sectional design study so we do not know about causality yet. This question could be addressed by future studies that look at personality and brain physiology over time to see how they affect each other.”

“Also, there are various possible implications of these findings, but there is not an established explanation for why we see these differences in cortical thickness,” Sweeney added.

“The study highlights the importance of personality in aging and in psychopathology. We only looked at one physiological measure in a small number of brain regions, but there is much more that could be investigated.”

The study, “Regional Cortical Thickness and Neuroticism Across the Lifespan“, was authored by Melissa Sweeney, Angeliki Tsapanou, and Yaakov Stern.