Salivary biomarkers in psychological stress diagnosis

Background: Nowadays, the search for biomarkers has attracted attention in medical and psychological sciences. The biomarkers are crucial to prevent diseases, to detect pathologies and to induce quality of life in patients. Recent studies evaluate stress biomarkers and provide information about physiological and psychological organism reactions to stressors. These biomarkers can be assessed via motoring corporal fluids (serum, plasma, urine and salivary fluid) and the proteins most used within stress salivary biomarkers are cortisol, α-amylase, proinflammatory cytokines, and catecholamines. The aim of this paper is to review systematically the scientific literature about the evaluation of salivary biomarkers in psychological stress diagnostic. Main Body: A systematic literature search review of Pubmed, Medline and Scopus database using the terms "salivary biomarkers” AND "psychological stress" AND “diagnostic” showed an increase in the number of studies using salivary biomarkers. It was analyzed all the existing articles (between 1997 and 2015). The inclusion criteria were: salivary biomarkers in diagnosis psychological stress, papers written in English. It was excluded the articles outside the scope of the subject, studies of animal disease models, stress methodologies and laboratory protocols, religious practices and stress; publications in languages other than English, and articles with unavailable information. After applying the methodology, 54 scientific articles were included in the study and analyzed. The review proved that salivary cortisol and alpha-amylase biomarkers are more used to diagnosis stress diseases. Of the 54 articles analyzed: 79% referred to cortisol biomarker as most biomarker used, followed by salivary amylase. These two salivary biomarkers jointly accounted 27% of the articles referred. Conclusions: This literature review is based on the contribution of salivary biomarkers to psychological stress diagnosis, understanding the diseases and their responses to treatment.