Changes in metabolic correlates of personality traits in healthy elderly women

Personality traits are generally known to be stable, although the brain changes with aging. Especially women experience striking alterations in the neuroendocrinergic system at menopause, which may cause considerable changes in personality traits and alter their underlying neural substrates. To investigate changes in the neural substrates underlying personality traits, we investigated metabolic correlates of personality traits in women before and after menopause. We obtained FDG PET images from 13 young (24.0±3.1 y) and 11 elderly females (66.8±3.3 y). Three factors of personality traits (novelty seeking (NS), harm avoidance (HA), reward dependence (RD)) were assessed using Cloninger's 240-item Temperament and Characteristic Inventory. Three ANCOVA maps were created in SPM2 (P < 0.01 uncorrected, k = 100), each constructed to assess the metabolic correlates of each temperament factor. In young females NS scores were negatively correlated with glucose metabolism in the right insula and right cingulate; in elderly females, the right cuneus. In young females HA scores were positively correlated with glucose metabolism in the right lingual gyrus; in elderly females, the left anterior cingulate and bilateral hippocampus. Only in elderly females, HA scores were negatively correlated with glucose metabolism in the right orbital gyrus and bilateral frontal gyri. In young females, RD scores were positively correlated with glucose metabolism in the bilateral frontal gyri and bilateral cingulate; in elderly females, the right middle frontal gyrus. In young females, RD scores were negatively correlated with glucose metabolism in the right precuneus; in elderly females, the left insula. We found that neural substrates underlying personality traits in females were dissociable across young and elderly women. These results may provide better understanding of differential prevalence and susceptibility to psychiatric illnesses in young and elderly females