Stress and the hypothalamic-pituitary-adrenal axis: How can the COVID-19 pandemic inform our understanding and treatment of acute insomnia?

Stress and sleep are very closely linked, and stressful life events can trigger acute insomnia. The ongoing COVID-19 pandemic is highly likely to represent one such stressful life event. Indeed, a wide range of cross-sectional studies demonstrate that the pandemic is associated with poor sleep and sleep disturbances. Given the high economic and health burden of insomnia disorder, strategies that can prevent and treat acute insomnia, and also prevent the transition from acute insomnia to insomnia disorder, are necessary. This narrative review outlines why the COVID-19 pandemic is a stressful life event, and why activation of the hypothalamic-pituitary-adrenal axis, as a biological marker of psychological stress, is likely to result in acute insomnia. Further, this review outlines how sleep disturbances might arise as a result of the COVID-19 pandemic, and why simultaneous hypothalamic-pituitary-adrenal axis measurement can inform the pathogenesis of acute insomnia. In particular, we focus on the cortisol awakening response as a marker of hypothalamic-pituitary-adrenal axis function, as cortisol is the end-product of the hypothalamic-pituitary-adrenal axis. From a research perspective, future opportunities include identifying individuals, or particular occupational or societal groups (e.g. frontline health staff), who are at high risk of developing acute insomnia, and intervening. From an acute insomnia treatment perspective, priorities include testing large-scale online behavioural interventions; examining if reducing the impact of stress is effective and, finally, assessing whether "sleep vaccination" can maintain good sleep health by preventing the occurrence of acute insomnia, by preventing the transition from acute insomnia to insomnia disorder.

Cortisol awakening response among Latinx and Black students transitioning to college prior to and during the COVID-19 pandemic.

Globally, the COVID-19 (coronavirus disease 2019) pandemic has resulted in abrupt shifts in ecological and social environments, including school contexts, which became predominately virtual. This study (1) examines the role of the COVID-19 pandemic (transitioning to college prior to vs. during the COVID-19 pandemic) on cortisol awakening response (CAR) - a biological marker of chronic psychosocial stress - and university belonging among Latinx and Black first-year college students; and (2) explores whether university belonging serves as a mediator in the relationship between the COVID-19 pandemic and CAR. Latinx and Black students who were in their first semester at a four-year public university in Los Angeles County - one of the United States' hot spots for COVID-19, were recruited for this study. Across two separate cohorts (fall 2019, fall 2020), participants (N = 136) completed an online survey and provided salivary samples to assess for morning cortisol levels. Findings revealed that students who transitioned to college during the COVID-19 pandemic exhibited a flatter CAR and lower levels of belonging than students who transitioned to college prior to the COVID-19 pandemic. Implications for intervention, programs and policies aimed at fostering positive transitions to college during the COVID-19 pandemic and beyond are discussed.