Social Isolation: A Narrative Review on the Dangerous Liaison between the Autonomic Nervous System and Inflammation

Abstract

Social isolation and feelings of loneliness are related to higher mortality and morbidity. Evidence from studies conducted during space missions, in space analogs, and during the COVID-19 pandemic underline the possible role of the autonomic nervous system in mediating this relation. Indeed, the activation of the sympathetic branch of the autonomic nervous system enhances the cardiovascular response and activates the transcription of pro-inflammatory genes, which leads to a stimulation of inflammatory activation. This response is adaptive in the short term, in that it allows one to cope with a situation perceived as a threat, but in the long term it has detrimental effects on mental and physical health, leading to mood deflection and an increased risk of cardiovascular disease, as well as imbalances in immune system activation. The aim of this narrative review is to present the contributions from space studies and insights from the lockdown period on the relationship between social isolation and autonomic nervous system activation, focusing on cardiovascular impairment and immune imbalance. Knowing the pathophysiological mechanisms underlying this relationship is important as it enables us to structure effective countermeasures for the new challenges that lie ahead: the lengthening of space missions and Mars exploration, the specter of future pandemics, and the aging of the population.

Stress, Dysregulation of Rhythms, and Bipolar Disorder: A Challenging Field of Research

“…Healthcare workers, who were under significant pressure due to the pandemic and had more dysregulation of personal and social rhythms, were found to be at greater risk for burnout syndrome and mood disorders [34][35][36][37]. The dysregulation of social rhythms negatively impacts the course and outcomes of chronic diseases and immune responses [38,39].…”