The present paper aims at reviewing and commenting on the relationships between sleep and circadian phasing alterations and neurodegenerative/neuroprogressive processes in mood disorder. We carried out a systematic review, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, in PubMed, PsycINFO, and Embase electronic databases for literature related to mood disorders, sleep disturbances, and neurodegenerative/neuroprogressive processes in relation to (1) neuroinflammation, (2) activation of the stress system, (3) oxidative stress, (4) accumulation of neurotoxic proteins, and (5) neuroprotection deficit. Seventy articles were collectively selected and analyzed. Experimental and clinical studies revealed that insomnia, conditions of sleep loss, and altered circadian sleep may favor neurodegeneration and neuroprogression in mood disorders. These sleep disturbances may induce a state of chronic inflammation by enhancing neuroinflammation, both directly and indirectly, via microglia and astrocytes activation. They may act as neurobiological stressors that by over-activating the stress system may negatively influence neural plasticity causing neuronal damage. In addition, sleep disturbances may favor the accumulation of neurotoxic proteins, favor oxidative stress, and a deficit in neuroprotection hence contributing to neurodegeneration and neuroprogression. Targeting sleep disturbances in the clinical practice may hold a neuroprotective value for mood disorders.

Background: Several data suggest that coronavirus disease 2019 (COVID-19) pandemic may exacerbate or trigger eating disorders (EDs). The aim of this paper was to summarize current literature studies on COVID pandemic and EDs.Methods: Literature search, study selection, methods, and quality evaluation were performed according to the preferred reporting items for systematic review and meta-analyses (PRISMA) guidelines.Results: A systematic search allowed the initial selection of 172 papers; 21 (12.2%) papers were eligible and included in the review. In selected studies, a total number of 29,108 subjects were enrolled (range: 10–11,391; mean/SD: 1,386 ± 2,800), 6,216 were men (21.4%), 22,703 were women (77.9%), and 189 (0.7%) were gender fluid or not declared. The mean age/SD of subjects was 30.2 ± 7.7. About 12 studies (57.1%) were online surveys, 4 (19.0%) were retrospective studies, 2 (9.5%) were qualitative studies, 2 (9.5%) were longitudinal cohort studies, and 1 was a social media survey (4.8%). Their analysis revealed five main findings: (1) changes in the routines of physical activities were related to the worsening of preoccupation on weight/body shape; (2) food access limitation during pandemic represented the risk factors for both triggering and exacerbating EDs; (3) restriction in healthcare facilities contributed to increase anxiety levels and to modify treatment compliance; (4) social isolation was related to the exacerbation of symptoms in patients with EDs who are home-confined with family members; and (5) conflicts and difficulties in relationships with “no way out” were the maintenance factors for ED symptoms, especially in adolescents and young adults.Conclusion: The COVID-19 pandemic had a negative impact on EDs that might be triggered by the exceptional conditions derived from COVID-19-related stress in predisposed subjects. Patients who were already affected by EDs experienced the worsening of their clinical conditions and related quality of life (QoL).