The role of hormonal, metabolic and inflammatory biomarkers on sleep and appetite in drug free patients with major depression: A systematic review

• Published in: Journal of affective disorders 2019-05, Vol.250, p.249-259
• Main Authors: Caroleo, Mariarita, Carbone, Elvira Anna, Primerano, Amedeo, Foti, Daniela, Brunetti, Antonio, Segura-Garcia, Cristina
• Format: Article
• Language: English
• Subjects: Appetite; Atypical depressive symptoms; Biomarkers; Major depressive disorder; Sleep; Systematic review
• ISSN: 0165-0327; 1573-2517
• DOI: 10.1016/j.jad.2019.03.015

•A systematic review on biomarkers of sleep and appetite regulation in MDD was done.•Higher leptin, ghrelin, cortisol and orexin levels are found in typical depression.•Lower IL-4, TNF-α and higher IL-2 and IL-6 were found in atypical depression.•Lower levels of BDNF were linked to neurovegetative changes in depression.•Nesfatin-1 is involved in stress reactions and sleep patterns in MDD. Major depressive disorder (MDD) is a complex and heterogeneous disorder in which clinical symptoms can widely differ among patients. Neurovegetative symptoms, i.e. decreased or increased appetite, changes in body weight and sleep disturbances, described as 'melancholic’ or ‘atypical’ features of a depressive episode, are the most variable symptoms among patients with MDD. We hypothesized biomarkers differences underlying this neurovegetative variability in major depression. We systematically reviewed, according to the PRISMA guidelines, the role of specific metabolic, hormonal and inflammatory biomarkers in drug-free MDD patients, that could have neurobiological effects on appetite, weight regulation and circadian rhythms, influencing eating behaviour and sleep patterns. All studies regarding the co-occurrence of disturbed sleep and appetite were examined. Besides the well-known leptin and ghrelin, other biomarkers such as BDNF, VEGF, NPY, orexin, and the recent discovered nesfatin-1 seem to be involved in neurovegetative changes in depressive disorders playing a role in the regulation of affective states, stress reactions and sleep patterns. Interestingly, based on the existing evidence, ghrelin, orexin and nesfatin-1 could be linked both to sleep and appetite regulation in depressed patients. Heterogeneous studies with low sample size. Despite the wide heterogeneity of results, studies on biomarkers of appetite and sleep in MDD are an interesting field of research to explain the neurobiological substrates of depressive symptoms that deserve further investigation.