The Neurocognitive Basis of Oral Health Decline in Schizophrenia: From Functional Impairment to Prevention

Background: Schizophrenia is strongly associated with severe oral health deterioration, driven by cognitive deficits, behavioral dysfunction, and medication-related biological changes. Objective: To examine how neurocognitive dysfunction in schizophrenia, particularly cognitive deficits, is associated with poorer oral hygiene control, motivation, and self-regulation, contributes to oral health decline by disrupting everyday oral hygiene behaviors and dental care engagement, and to discuss the implications of this framework for interdisciplinary prevention strategies. Methods: This manuscript follows a narrative review design aimed at conceptually integrating evidence on neurocognitive mechanisms underlying oral health decline in schizophrenia. To identify relevant literature, a targeted search of PubMed/MEDLINE, Scopus, and Web of Science was conducted, covering publications from 2000 to 2025. The search strategy was used to support thematic exploration and conceptual synthesis, rather than to perform a systematic study selection or quantitative evidence aggregation. This narrative review summarizes findings from 90 peer-reviewed studies selected from the available literature. Results: Executive dysfunction, attentional deficits, and low motivation impair routine oral hygiene and delay dental care-seeking. Antipsychotic-induced xerostomia, metabolic disturbances, oxidative stress, immune dysregulation, and oral microbiome dysbiosis accelerate periodontal breakdown and caries progression. These interacting processes generate a self-reinforcing cycle of inflammation, tissue destruction, and treatment avoidance. Epidemiological data show markedly elevated DMFT/DMFS indices and up to a three-fold higher risk of edentulism compared with the general population. Emerging evidence suggests that integrated psychiatric–dental care models may be associated with improvements in oral health and care engagement, although current findings are largely preliminary and based on small or heterogeneous study populations, including related neurocognitive disorders. Conclusions: Unlike existing epidemiological syntheses, this review highlights oral health deterioration in schizophrenia as a functionally mediated consequence of neurocognitive impairment, underscoring the need for preventive approaches aligned with patients’ cognitive and motivational capacities.