Analysis of Associations of Temperament and Character Traits with Serum Cortisol Levels in Sakha (Yakut) Men Taking Account of Childhood Stress

The aim of the present work was to test the hypothesis that temperament and personality traits can affect serum cortisol levels and may depend on stressful situations experienced in childhood. The study cohort included healthy young men (n = 121) of Yakut ethnicity aged 18–27 years. Personality traits were assessed using the Cloninger TCI-125 Temperament and Character Scales. Serum cortisol levels were assessed by enzyme-linked immunosorbent assay (ELISA). The reward dependence temperament trait was found to be associated with higher blood cortisol levels (p = 0.04). Stressful situations experienced in childhood were associated with lower scores on the self-transcendence character scale (p = 0.049) but did not significantly affect cortisol levels in adults. In individuals with high levels of stress, significant correlations were found between the novelty-seeking (r = 0.33) and self-directedness (r = 0.36) indexes and the cortisol level, which may reflect the prolonged effect of stress on the functioning of the adrenal cortex. The results suggest associations between the reward dependence temperament trait and the blood cortisol level, as well as between early life stress and the self-transcendence character trait.