THE INTERACTION BETWEEN SALIVARY CORTISOL AND DHEA DURING ACUTE PSYCHOSOCIAL STRESS IN SLEEP DEPRIVED INDIVIDUALS
Petrosky, Michaella Anne
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Sleep deprivation can impair cognitive and emotional processes, especially those regulated by the prefrontal cortex and medial temporal lobe (i.e., hippocampus, amygdala). Stress and increased cortisol levels have been found to have similar detrimental effects. More recently, research has found that dehydroepiandroeterone (DHEA), an antagonist to cortisol, may counter the negative consequences of stress and even provide beneficial results to individuals under stress. However, very little is known regarding the relationship between DHEA and cortisol when individuals are both sleep deprived and stressed. The aim of the current study was to explore the relationship between DHEA and cortisol during an acute psychological stressor in sleep-deprived individuals. It was hypothesized that sleep deprivation would disrupt the protective effects of DHEA, as evidenced by a larger interaction between cortisol and DHEA in sleep deprived individuals after an acute stressor, as compared to controls. Specifically, high cortisol and low DHEA would be seen in sleep deprived participants compared to low cortisol and high DHEA in control participants. Additionally, it was hypothesized that if such a difference exists between groups, this difference would predict changes in affect. More specifically, individuals with low cortisol and high DHEA would have decreased negative affect, whereas individuals with high cortisol and low DHEA would have increased negative affect. Twenty-eight participants were split evenly between the sleep deprivation group and control group. Sleep deprivation was induced by wakefulness for 24 hours while controls slept for 8 hours. Stress was induced through the Trier Social Stress Test. Saliva samples and the Positive and Negative Affect Scale (PANAS) were collected at three time points—before, immediately after, and 20 minutes after the acute stressor. There was no significant difference observed in the cortisol to DHEA ratio between sleep deprived and non-sleep deprived individuals after an acute stressor. These findings suggested that the combined effects of sleep deprivation and stress did not disrupt the protective effects of DHEA on cortisol. Future research should be conducted to fully elucidate these relationships.