Traumatic stress and the circadian system: neurobiology, timing and treatment of posttraumatic chronodisruption

Abstract

Background: Humans have an evolutionary need for a well-preserved internal 'clock', adjusted to the 24-hour rotation period of our planet. This intrinsic circadian timing system enables the temporal organization of numerous physiologic processes, from gene expression to behaviour. The human circadian system is tightly and bidirectionally interconnected to the human stress system, as both systems regulate each other's activity along the anticipated diurnal challenges. The understanding of the temporal relationship between stressors and stress responses is critical in the molecular pathophysiology of stress-and trauma-related diseases, such as posttraumatic stress disorder (PTSD). Objectives/Methods: In this narrative review, we present the functional components of the stress and circadian system and their multilevel interactions and discuss how traumatic stress can affect the harmonious interplay between the two systems. Results: Circadian dysregulation after trauma exposure (posttraumatic chronodisruption) may represent a core feature of trauma-related disorders mediating enduring neurobiological correlates of traumatic stress through a loss of the temporal order at different organizational levels. Posttraumatic chronodisruption may, thus, affect fundamental properties of neuroendocrine, immune and autonomic systems, leading to a breakdown of biobehavioral adaptive mechanisms with increased stress sensitivity and vulnerability. Given that many traumatic events occur in the late evening or night hours, we also describe how the time of day of trauma exposure can differentially affect the stress system and, finally, discuss potential chronotherapeutic interventions. Conclusion: Understanding the stress-related mechanisms susceptible to chronodisruption and their role in PTSD could deliver new insights into stress pathophysiology, provide better psychochronobiological treatment alternatives and enhance preventive strategies in stressexposed populations.

Prolonged Exposure to Social Stress Impairs Homeostatic Sleep Regulation

“…Further investigation is required to assess the differential role of frontal and parietal SWA power in relation to sleep debt of different intensity in the dark and light periods independently. Moreover, our data potentially suggests that the sleep impairments induced by chronic stress exposure could be due to either a deficient process S ( Borbely, 1982b ; Borbely and Wirz-Justice, 1982 ; Frey et al, 2012b ), or a deficient process C due to circadian dysregulation ( Agorastos et al, 2019 ; Agorastos and Olff, 2020 ), or a discoordination/asynchrony between both processes.…”

Mental health risks differentially associated with immunocompromised status among healthcare workers and family members at the pandemic outset

“…This notion may be evidenced by the large difference in ‘insufficient sleep’ between on-shift work days compared to off-shift work days. The implication is that, for clinical providers, disrupted circadian rhythm has the potential to significantly reduce resilience and increase risks for distress and burnout if not addressed ( Amanullah and Shankar, 2020 ; Agorastos, Agorastos and Olff, 2020 ; Heath et al., 2020 ).…”

Oxidative Dysregulation in Early Life Stress and Posttraumatic Stress Disorder: A Comprehensive Review

“…Circadian dysregulation and sleep disturbances represent a core feature of traumaticstress-related disorders, often closely related to the severity of PTSD psychopathology [211][212][213]. Circadian dysregulation after traumatic stress can lead to a breakdown of biological adaptive mechanisms and may constitute another crucial link between traumatic stress and OXS [214,215]. Normally, a proper temporal order of biological systems is associated with balanced restorative properties throughout the body, allowing antioxidant processes to take over [216,217].…”