Evaluation of periodontitis in hospital outpatients with major depressive disorder. A focus on gingival and circulating cytokines

Correlation between the Oral and Mental Health of University Students in Serbia-A Cross-Sectional Study

BACKGROUND

This cross-sectional study aimed to assess the correlation between subjective oral health status and mental health in a group of university students in Serbia.

METHODS

The study included 948 students, aged between 18 and 27, from the Faculty of Medical Sciences, University of Kragujevac, Serbia, and was conducted in 2020. The World Health Organization's Oral Health Questionnaire for Adults was utilized to evaluate the respondents' self-perceived oral health and oral hygiene practices. The existence of depressive symptoms was evaluated using the Beck Depression Inventory-II (BDI-II), and the Zung self-rating anxiety scale (SAS) was used for determining anxiety symptoms.

RESULTS

It is observed that 28.9% of respondents exhibit symptoms of depression and 42.3% showed symptoms of anxiety. Results show that students with severe depression and anxiety symptoms very often reported lower self-perceived oral health and oral health problems. Although the nature of this relationship has not been thoroughly evaluated, several studies have shown a mutually dependent connection between oral health and mental health.

CONCLUSIONS

The results suggest that some aspects of oral health are associated with higher risks of developing symptoms of depression or anxiety, and vice versa.

Treg cell: Critical role of regulatory T-cells in depression

Depression is a highly prevalent disorder of the central nervous system. The neuropsychiatric symptoms of clinical depression are persistent and include fatigue, anorexia, weight loss, altered sleep patterns, hyperalgesia, melancholia, anxiety, and impaired social behaviours. Mounting evidences suggest that neuroinflammation triggers dysregulated cellular immunity and increases susceptibility to psychiatric diseases. Neuroimmune responses have transformed the clinical approach to depression because of their roles in its pathophysiology and their therapeutic potential. In particular, activated regulatory T (Treg) cells play an increasingly evident role in the inflammatory immune response. In this review, we summarized the available data and discussed in depth the fundamental roles of Tregs in the pathogenesis of depression, as well as the clinical therapeutic potential of Tregs. We aimed to provide recent information regarding the potential of Tregs as immune-modulating biologics for the treatment and prevention of long-term neuropsychiatric symptoms of depression.

Biomarkers common for inflammatory periodontal disease and depression: A systematic review

Background

Dysregulated immune response arising in the periphery can induce depressive symptoms through neuroimmune interactions. Inflammatory oral pathology can be a potent inducer of chronic neuroimmune response relevant to depression. We aimed to synthesize available evidence for the association between inflammatory periodontal diseases (IPD) and major depression (MD) in relation to a broad range of biomarkers.

Methods

Medline, Embase, PsycInfo, Cochrane Library, Web of Science and Scopus databases were searched from inception until January 27, 2022. Search terms included subject headings and synonyms for inflammatory periodontal disease and depression. Studies that reported data on both depression and inflammatory periodontal disease as categories along with measurement of a biomarker were considered. Two reviewers independently selected the articles for inclusion, extracted data and assessed the quality of each study. The protocol for this study was registered with PROSPERO, CRD42021215524.

Results

Twenty-eight studies were included in the final review-eleven cross-sectional studies, seven case-control studies, and six prospective cohort studies conducted in humans; the remaining four were experimental animal studies. Eighteen studies including all animal studies reported a positive association between depression and periodontal disease; one study reported a negative association and another nine studies found no such associations. Twenty studies reported mixed associations between IPD and biomarkers (i.e, salivary, serum, urine or gingival crevicular fluid cortisol, C reactive protein, cytokines, etc.). Biomarkers related to depression were gingival crevicular fluid cortisol, interleukin 6 (IL-6), Il-1β, immunoglobulin G against Bacterioides forsythus; root canal lipopolysaccharides; blood IL-6, IL-1β, cortisol, advanced oxidation protein products, nitric oxide metabolites, lipid hydroperoxides and trapping antioxidant parameter; whereas five studies found no associations between depression and a biomarker. Although animal studies showed interaction of immune, inflammatory and neurotrophic biomarkers in the relationship between depression and periodontal disease, human studies showed mixed findings. In most studies, there were risks of bias due to the sample selection and assessment protocol. Study heterogeneity and limited number of comparable studies reporting on shared biomarkers precluded a meta-analysis.

Conclusion

Immune-inflammatory contribution to depression was evident in the context of inflammatory periodontal diseases, but whether biomarkers mediate the associations between IPD and MD needs to be tested through methodologically rigorous studies aiming specifically at this hypothesis.

Association Between Mental Health and Oral Health Status and Care Utilization

Studies have shown that mental health and oral health may be correlated, with associations demonstrated between mental health problems and tooth loss, periodontal disease, and tooth decay. The COVID-19 pandemic had alarming implications for individuals' and communities' mental and emotional health. This study examined the associations between mental health status, oral health status, and oral healthcare utilization and highlighted the impact of COVID-19 on mental health. Additionally, this study examines specific sociodemographic factors that may amplify oral health disparities. A nationally representative survey was conducted to capture attitudes, experiences, and behaviors related to oral health, mental health, and unmet oral health needs. Eighteen percent of respondents were categorized as having poor mental health. Visiting the dentist in the last year was more common amongst individuals with good mental health. From the logistic regression model, mental health status, age group, race/ethnicity, education, and last dental visit were all significantly associated with of oral health status. Mental health status, age group, and income groups were all significantly associated with unmet oral health need. Future work should focus on the mental-oral health association, including determining ways to improve oral healthcare utilization and oral health status among people with poorer mental health.

Influence of Depression and Anxiety on Non-Surgical Periodontal Treatment Outcomes: A 6-Month Prospective Study

Periodontal treatment could be worsened by risk factors. Depression and anxiety have been suggested as potentially influencing periodontal treatment outcomes. The aim of this study was to determine their association with non-surgical periodontal treatment outcomes in patients with generalized severe periodontitis (stage III/IV generalized periodontitis) at 6 months. A total of 68 patients diagnosed with generalized severe periodontitis were treated with scaling and root planing (SRP) and were followed at 3 and 6 months. The data of the 54 patients that followed the entire protocol were considered for analysis. Depression and anxiety levels were determined at baseline by the Beck Depression Inventory (BDI) and State-Trait Inventory (STAI) questionnaires. The association between psychological scores and periodontal parameters was evaluated by multivariate analysis. At 3 and 6 months, SRP induced an improvement for all periodontal parameters (plaque index (PI), bleeding on probing (BOP), periodontal probing depth (PPD) and clinical attachment loss (CAL)). BDI and STAI scores were associated with the evolution of PI, BOP, mean PPD and number of sites with PPD > 3 mm and with CAL > 3 mm. Depression and anxiety should be considered as risk factors for SRP and the identification of at-risk patients should be performed using well-established tools.

Analysis of cytokine levels, T regulatory cells and serotonin content in patients with depression

Alterations in peripheral serotonin concentrations and an imbalanced immune system have been reported in patients with depression. Cytokines and T regulatory (Treg) cells may play an important role in the development of depression. This study investigates the levels of cytokines and Treg cells, as well as the concentration of serotonin (5-HT) in the blood of 89 patients suffering from depression and 89 healthy participants between two acquisitions. We investigated the state of health before (T1) and after (T2) psychological and pharmacological therapy. Both cytokine (IL-6, IL-10, TNF-α, and INF-γ) and 5-HT levels in the blood were measured by enzyme-linked immunosorbent assays. The levels of CD4⁺ CD25⁺ Treg cells were determined by flow cytometric analysis. Patients with depression showed significantly higher serum levels of IL-6 and INF-γ, no altered serum levels of IL-10 and TNF-α, and decreased platelet and serum 5-HT levels compared with healthy participants at the first acquisition. In addition, the symptoms of depression and anxiety, the TNF-α level, and the amount of CD4⁺ CD25⁺ cells in the blood were decreased from the first to the second acquisition. Further, a correlation between IL-6 and platelet 5-HT has been observed in patients. An imbalance of the immune system in patients with depression and an association of the serotonergic system and cytokines were observed. These results indicate that the development of depression might be related to several interacting proteins, including cytokines and 5-HT, and the treatment affects imbalances of these factors.

The Possible Causal Link of Periodontitis to Neuropsychiatric Disorders: More Than Psychosocial Mechanisms

Increasing evidence implies a possible causal link between periodontitis and neuropsychiatric disorders, such as Alzheimer's disease (AD) and major depression (MD). A possible mechanism underlying such a link can be explained by neuroinflammation induced by chronic systemic inflammation. This review article focuses on an overview of the biological and epidemiological evidence for a feasible causal link of periodontitis to neuropsychiatric disorders, including AD, MD, Parkinson's disease, and schizophrenia, as well as the neurological event, ischemic stroke. If there is such a link, a broad spectrum of neuropsychiatric disorders associated with neuroinflammation could be preventable and modifiable by simple daily dealings for oral hygiene. However, the notion that periodontitis is a risk factor for neuropsychiatric disorders remains to be effectively substantiated.

Melatonin and periodontal tissues: Molecular and clinical perspectives

Periodontal disease is a frequent chronic inflammatory pathology that implies the destruction of the tissues supporting the teeth, which represents a high sanitary cost. It usually appears associated with other systemic conditions such as diabetes, metabolic syndrome, depression and Alzheimer disease among others. The presence of melatonin and its receptors in the oral cavity supports the hypothesis that this hormone could play a role in homeostasis of periodontal tissues. In the present review we will discuss the potential role of melatonin, a circadian synchronizing hormone, with proved antiinflammatory and antioxidant profile, in the pathogenesis and treatment of periodontitis. Particular emphasis will be placed on the role of the indolamine in the treatment of periodontal disease when this oral condition is comorbid with other pathologies that would also benefit from the therapeutic potential of melatonin and its analogs through diverse mechanisms.