Neurobiological Trajectories Involving Social Isolation in PTSD: A Systematic Review

Abstract

Social isolation (SI) stress has been recognized as a major risk factor of morbidity in humans and animals, exerting damaging effects at the physical and mental health levels. Posttraumatic stress disorder (PTSD), on the other hand, occurs as a result of experiencing serious, life-threatening, traumatic events and involves involuntary re-experiencing trauma (intrusion), avoidance symptoms, and distortions of cognition and emotional arousal. The literature shows that PTSD is affected by genetic predisposition and triggers a large neurocircuitry involving the amygdala, insula, hippocampus, anterior cingulate- and prefrontal-cortex, and affects the function of the neuroendocrine and immune systems. Social isolation seems to influence the predisposition, onset and outcome of PTSD in humans, whereas it constitutes a valid model of the disorder in animals. According to the PRISMA (preferred reporting items for systematic reviews and meta-analyses) protocol, we systematically reviewed all original studies involving the neurobiological trajectories between SI and PTSD published till July 2019 (database: PubMed/Medline). Out of 274 studies, 10 met the inclusion criteria. We present the results of the retrieved studies in terms of hypothalamic-pituitary-adrenal (HPA)-axis and endocannabinoid system function, immune reactions, neuroplasticity, novel pharmacological targets, and shortening of telomere length, which confirm a synergistic effect on a neurobiological level between the two entities.

Factors associated with COVID-19 pandemic induced post-traumatic stress symptoms among adults living with and without HIV in Nigeria: a cross-sectional study

“…The association between PTSD and loneliness may reflect an overlap because people who experience both have a persistent sense of threat and hypervigilance for threats [28,29], the shared experience of trauma exposure [30], avoidance symptoms [31], and negative evaluation of the world [32]. Social support is protective against the development of PTSD [33] while social isolation influences the predisposition of people to and onset of PTSD [34].…”

Mechanisms of Susceptibility and Resilience to PTSD: Role of Dopamine Metabolism and BDNF Expression in the Hippocampus

“…Earlier we showed that following PS, DA metabolism was impaired while concentrations of DA metabolites were increased [ 16 ]. The hippocampus participates in the regulation of anxiety [ 17 , 18 , 19 , 20 , 21 , 22 ]. The hippocampus interacts with both cortical and subcortical brain regions that regulate emotions and responses to stress.…”

The role of healthy emotionality in the relationship between fear of COVID-19 and mental health problems: a cross-sectional study

“…Attention refers to intentional selective attention to positive information. Following stressful events, prolonged or repeated attention to negative aspects of these impairs the hypothalamic–pituitary–adrenal system, predicts depression and is associated with health problems (Vlachos et al, 2020 ). Additionally, the inability to disengage attention away from threat plays a significant role in the etiology and maintenance of anxiety disorders.…”