Sleep deprivation increases stress reactivity in response to public speaking
Several studies have profiled the impact of sleep deprivation/partial sleep deprivation on stress hormones but little work has investigated the impact of experimentally reduced sleep on physiological stress reactivity.
In a new study published in the journal Health Psychology Jared Minkel and colleagues recruited 26 participants, 12 of whom were randomized to one night of sleep deprivation while the other 14 slept according to a 9-hour sleep opportunity. The next day, between 5 and 5.30pm, all participants took part in the Trier Social Stress Test (TSST), which involved participants being told that they were required to prepare a speech and perform a mental arithmetic task in front of a three-person panel. The TSST reliably induces stress in humans, evidenced in self-reported stress ratings, autonomic activity and stress hormone secretion. Minkel and colleagues measured salivary cortisol and alpha-amylase twice prior to the speech (anticipation period) and three times after the stress test.
Results showed that, for both groups, the social stress test reliably increased cortisol and alpha-amylase. Furthermore, the sleep deprived group evidenced greater cortisol levels prior to the test and in response to the stress test, compared with the well-rested control group.
The authors note that elevated cortisol is associated with depression and obesity – conditions linked to disrupted and/or insufficient sleep – thus sleep disturbance could be an important target for intervention in these groups. They also note that more real-world sleep loss (e.g. sleep restriction) should be examined in the context of sleep curtailment, stress exposure/reactivity and health outcomes.
Minkel, J., Moreta, M., Muto, J., Htalk, O., Jones, C., Basner, M., Dinges, D. (2014). Sleep deprivation potentiates hpa axis stress reactivity in healthy adults. Healthy Psychology, in print.