OBJECTIVE: Personality traits can be the basis for individual differences in the biological response of stress. To date, many psychobiological studies have been conducted to clarify the relationship between personality and biological reactivity to stress. This review summarizes the most important findings in this area of research. RESULTS: Key findings related to the relationship between personality factors and stress-sensitive biological systems in four research models have been summarized; model of psychosocial characteristics, model based on Rumination and Emotional Inhibition, Eysenck’s biopsychological model, and Five-Factor Approach of Personality. CONCLUSION: According to the results of this review, it can be concluded that personality typology of individuals influenced their biological reactivity to stressful events. Understanding the biological basis of personality can help to better understand vulnerability to stress. Future research can be continuing based on framework of the four models.
alpha-Amylases ; Biomarkers ; Hydrocortisone ; Immunoglobulin A ; Individuality ; Life Change Events ; Stress, Psychological

Objective: The association between preterm birth (PTB), Spindle and Kinetochore Associated Complex Subunit 2 gene (SKA2), cortisol and anxiety have been shown, but in this study, we aimed to clarify whether the expression of the SKA2 gene plays a role in interleukin1β (IL-1β) level since increasing level of IL-1β is linked with PTB. Methods: The case-control study was conducted on 49 and 51 women with preterm and term delivery, respectively. The score of anxiety was ranked according to the Spielberger state trait Anxiety Inventory. The concentration of cortisol and IL-1β was determined by the ELISA method. The expression of SKA2 gene was assessed by the quantitative real time real time polymerase chain reaction (qRT-PCR). The western blot analysis was also performed to confirm the expression of SKA2 at the levels of protein. Results: The results showed that the gene/protein expression of SKA2, the concentrations of cortisol and IL-1β were significantly higher in the preterm than the term group. In the preterm group, the expression of SKA2 was positively correlated to the other factors including cortisol, IL-1β, and the degree of anxiety. Conclusion Our findings suggest that the expression of SKA2 was correlated positively to the levels of cortisol, IL-1β and the rate of anxiety in women with PTB.

OBJECTIVE: The purpose of this study was to evaluate the salivary testosterone levels under psychological stress and its relationship with rumination and five personality traits in medical students. METHODS: A total of 58 medical students, who wanted to participate in the final exam, were selected by simple random sampling. Two months before the exam, in the basal conditions, the NEO Inventory short form, and the Emotional Control Questionnaire (ECQ) were completed. Saliva samples were taken from students in both the basal conditions and under exam stress. Salivary testosterone was measured by ELISA. Data was analyzed using multivariate analysis of variance with repeated measures, paired samples t-test, Pearson correlation and stepwise regression analysis. RESULTS: Salivary testosterone level of men showed a significant increase under exam stress (p<0.05). However, a non-significant although substantial reduction observed in women. A significant correlation was found between extroversion (r=-0.33) and openness to experience (r=0.30) with salivary testosterone (p<0.05). Extraversion, aggression control and emotional inhibition predicted 28% of variance of salivary testosterone under stress. CONCLUSION: Salivary testosterone reactivity to stress can be determined by sexual differences, personality traits, and emotional control variables which may decrease or increase stress effects on biological responses, especially the salivary testosterone.
Aggression ; Enzyme-Linked Immunosorbent Assay ; Extraversion (Psychology) ; Female ; Humans ; Male ; Multivariate Analysis ; Saliva ; Stress, Psychological* ; Students, Medical* ; Testosterone*