The Effect Of Chronotype On Psychological Stress Of College Students

With the accelerated pace of modern life,the recurrence and instability of the COVID-19 epidemic have forced college students to be exposed to a state of stress.Chronotype,which is a person’s circadian characteristics throughout a day,play an important role in the physical and mental health of college students.Starting from the perspective of sleep,this study explored the influence of daily cycle type on psychological stress through three sub-studies,and explored the possible internal mechanism between them.In study 1,68 college students were selected to use cortisol awakening response(CAR)as a physiological index of psychological stress to explore the relationship between chronotype and CAR as well as the physiological mechanism behind sleep and psychological problems.The results showed that:(1)there were significant gender differences in the baseline cortisol level after waking up in the morning,and the baseline cortisol level of girls was significantly higher than boys.(2)The chronotype negatively predicted CAR: the more favored the morning type,the lower the CAR level.In study 2,836 college students were selected for the perceived stress response scale(PSRS),which is widely used abroad and has good reliability and validity.The results showed that five factors were obtained from exploratory factor analysis,which were: response to overwork,response to social conflict,response to social evaluation,response to failure and long-term response.The cumulative variance interpretation rate was 53.00%;The confirmatory factor analysis showed that all indexes of the model fit well.The internal consistency reliability of the five subscales of the Chinese version of PSRS is between 0.73 and 0.76.The retest reliability is between 0.60 and 0.76.The structural stability,reliability and validity of the Chinese version of PSRS meet the requirements of psychological measurement,and can be used as an effective tool to measure the perceived stress response of Chinese college students.Study 3 explored the relationship between chronotype and psychological stress response in a large sample range,and explored the intermediary mechanism between them.490 college students were tested with the perceived stress response scale,the morning and evening questionnaire-19 and bedtime procrastination scale revised in Study 2.The results showed that:(1)The type of university chronotype was negatively correlated with bedtime procrastination,psychological stress response and all dimensions;bedtime procrastination was positively correlated with psychological stress response and all dimensions.(2)Sleep procrastination plays a mediating role between chronotype and stress response,especially in the dimensions of stress response to overwork and social conflict.In conclusion,both physiological CAR differences and subjective reported psychological stress response showed that the more night oriented the chronotype,the higher the perceived psychological stress response level,and sleep procrastination played a mediating role between the two.By combining subjective and objective methods to measure the level of individual psychological stress response,this study can more comprehensively and reliably investigate the influence of the type of university chronotype on psychological stress,and provide theoretical support for the intervention and prevention of mental health development of college students from the perspective of sleep.