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.

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.