Human social isolation and stress: a systematic review of different contexts and recommendations for future studies

Abstract Objectives The emergence of the coronavirus disease 2019 (COVID-19) pandemic and subsequent lockdowns and social distancing measures adopted worldwide raised questions about the possible health effects of human social isolation. Methods We conducted a systematic review on PubMed, Scopus, and Embase electronic databases using terms related to human social isolation - defined as the isolation of an individual from regular routines and usual social contact - and psychological stress, searching for simulated or naturalistic isolation environments. We present the main results, as well as the validity and limitations of each model. PROSPERO registry number: CRD42021241880. Results Despite the diversity of contexts reviewed, some outcomes almost ubiquitously relate to psychological stress, i.e., longer periods, expectation of a longer period, confinement, lack of social interaction, and support. Based on the results, and considering that most studies were not designed for the purpose of understanding isolation itself, we propose a group of recommendations for future experimental or naturalistic research on the topic. Conclusion Evidence on the impact of different situations in which individuals are subjected to social isolation can assist in development of directed preventive strategies to support people under similar circumstances. Such strategies might increase the general public's compliance with social distancing as a non-pharmacological intervention for emerging infectious diseases.

Psychometric properties of the Brazilian version of the Pittsburgh Sleep Quality Index Addendum for PTSD (PSQI-A)

Objective: Sleep disturbances play a fundamental role in the pathophysiology posttraumatic stress disorder (PTSD), and are not only a secondary feature. The aim of this study was to validate and assess the psychometric properties of the Brazilian version of the Pittsburgh Sleep Quality Index Addendum for PTSD (PSQI-A-BR), a self-report instrument designed to assess the frequency of seven disruptive nocturnal behaviors, in a sample of participants with and without PTSD. Methods: PSQI-A was translated into Brazilian Portuguese and applied to a convenience sample of 190 volunteers, with and without PTSD, who had sought treatment for the consequences of a traumatic event. Results: The PSQI-A-BR displayed satisfactory internal consistency (Cronbach's coefficient of 0.83 between all items) and convergent validity with the Clinician Administered PTSD Scale (CAPS), even when excluding sleep-related items (r = 0.52). Test-retest yielded high agreement in the global PSQI-A-BR, with good stability over time (r = 0.88). A global PSQI-A-BR cutoff score of 7 yielded a sensitivity of 79%, specificity of 64%, and a global score of 7 yielded a positive predictive value of 93% for discriminating participants with PTSD from those without PTSD. Conclusion: The PSQI-A-BR is a valid instrument for PTSD assessment, applicable to both clinical and research settings. .

Repercussões imunológicas dos distúrbios do sono: o eixo hipotálamo-pituitária-adrenal como fator modulador / Immune outcomes of sleep disorders: the hypothalamic-pituitary-adrenal axis as a modulatory factor

OBJETIVO: Revisar a literatura a respeito da interação entre sono e sistema imunológico. MÉTODO: Busca no Web of Science e no PubMed com os descritores: sono, privação de sono, estresse, eixo hipotálamo-pituitária-adrenal, sistema imunológico e doenças auto-imunes. RESULTADOS: Foram encontrados 588 artigos no Web of Science. As 61 referências mais significativas e mais relacionadas aos objetivos do estudo foram utilizadas. Foram incluídos artigos originais e de revisão. CONCLUSÃO: A privação de sono e o sistema imunológico exercem e sofrem influências mútuas. A privação de sono é considerada um estressor, uma vez que induz a elevação do cortisol em seres humanos - ou da corticosterona em roedores. Os glicocorticóides, por sua vez, exercem um efeito imunossupressor. Por essas razões, foi proposto que o aumento da ativação do eixo hipotálamo-pituitária-adrenal seja um importante mediador das alterações imunológicas observadas em pacientes com insônia ou privados de sono.

OBJECTIVE: To review the literature on the interaction between sleep and the immune system. METHOD: A search on Web of Science and Pubmed database including the keywords sleep, sleep deprivation, stress, hypothalamic-pituitary-adrenal axis, immune system, and autoimmune diseases. RESULTS: On Web of Science, 588 publications were retrieved; 61 references, more significant and closer to our objective, were used, including original articles and review papers. CONCLUSION: Sleep deprivation and immune system exert a bidirectional influence on each other. Since sleep deprivation is considered a stressor, inasmuch as it induces elevation of cortisol or corticosterone levels in humans and rodents, respectively, and given the well-known immunosuppressive effect of glucocorticoids, we propose that increased activation of the hypothalamic-pituitary-adrenal axis is a major mediator of the immune alterations observed in patients with insomnia or in sleep deprived subjects.