Post-awakening salivary alpha-amylase as modulator of treatment response in patients with burnout and major depression

Severity of depressive symptoms moderates the sympathoinhibitory effect of local skin warming following exposure to a social stressor

Depression is the leading cause of disease burden globally. Existing antidepressant treatments that target the central nervous system have limited efficacy and come at the cost of significant side effects. Thus, there is growing interest in novel therapeutic interventions for the prevention and treatment of depression, including interventions that target interoceptive signaling. The thermosensory system may hold particular promise, given evidence that depression is associated with impairments in thermosensory functioning, and that whole-body hyperthermia produces an antidepressant effect in patients with major depressive disorder. In this study, we investigated whether the severity of depressive symptoms in a non-clinical population moderated the effect of local skin warming on subjective and physiological stress responses following exposure to an acute social stressor. Following exposure to the stressor, participants (N = 90) rested their arm on a heat blanket that was either turned on (local skin warming condition) or left off (control condition). We demonstrate that local skin warming increased fingertip temperature, a marker of reduced sympathetic nervous system activity, but only for participants with high levels of depressive symptoms. While local skin warming also inhibited salivary alpha amylase, severity of depressive symptoms did not moderate this effect, and no effect was found for electrodermal activity. These data highlight the importance of incorporating peripheral physiology in our conceptualization of the pathophysiology of depression and show that changes in sympathetic nervous system activity may underpin the antidepressant effect of warm stimuli.

Cross-sectional analysis reveals COVID-19 pandemic community lockdown was linked to dysregulated cortisol and salivary alpha amylase in children

The COVID-19 pandemic altered everyday life starting in March 2020. These alterations extended to the lives of children as their normal routines were disrupted by community lockdowns, online learning, limited in-person social contact, increased screen time, and reduced physical activity. Considerable research has investigated the physical health impact of COVID-19 infection, but far fewer studies have investigated the physiological impact of stressful pandemic-related changes to daily life, especially in children. The purpose of this study was to leverage an ongoing clinical trial to investigate physiological consequences associated with chronic stress of pandemic community lockdown on children. As a part of the clinical trial, children provided saliva samples. Saliva samples were analyzed for cortisol and salivary alpha amylase (sAA) content. This secondary cross-sectional analysis included 94 preadolescent children located within the Greater Boston, Massachusetts community. Children participated in the study either before, during, or following the pandemic community lockdown to form three groups for comparison. In response to chronic stress caused by the pandemic community lockdown, participants demonstrated dysregulation of fast-acting catecholamine response of the locus-coeruleus-norepinephrine system and slower-acting glucocorticoid response, resulting in an asymmetrical relationship of hypocortisolism (M = 0.78 ± 0.19 μg/mL, p < 0.001) paired with higher sAA (M = 12.73 ± 4.06 U/mL, p = 0.01). Results suggest that the abrupt COVID-19 disruption to daily life, including the stressful experience of community lockdown, had physiological effects on typically developing children. Further research is required to investigate mental health outcomes of children following the chronic stress of the pandemic community lockdown.