Is there an association between oral health and depression? A systematic review

Depression plays a pivotal role in the global disease burden and one of the foremost causes of disability worldwide. Empirical evidence highlighted the association between depression and oral health. However, how these conditions are associated with one another and what mechanism underlies these associations is still obscure and unsure. This systematic review aimed to explore the association between oral health and depression. Electronic search was carried out for studies related to “Oral health and Depression” through PubMed and Google Scholar published in English language from 2018 to 2023. Articles that explored association between oral health and depression either as outcome or independent variable were considered. Quality of the 16 retrieved and included articles (8 cross-sectional, 3 longitudinal, 2 cohort studies, 2 systematic reviews, and 1 systematic review and meta-analysis) were assessed through the Joanna Briggs Institute – critical appraisal checklist for observational studies. Depression and oral health were considered as outcome in 7 and 6 articles respectively. Results revealed a two-way interaction between depression and oral health. Persons with poor oral health, through psychological mechanism develops depression due to reduced nutrition, chewing capacity and aesthetics resulting in lower self-esteem, social isolation/ lower social interactions and life satisfaction. Depressed subject’s oral health is impacted through biological mechanism where the anti-depressants cause side effects including reduced salivary secretion and rise in lactobacillus counts. Besides, behavioral mechanism including abandoning oral hygiene practices and dietary negligence also negatively impacts their oral health. A bidirectional association exists between depression and oral health, as certain oral health variables could have an impact on a patient's well-being and those who are depressed possibly have poor oral health.