Associations Between Mental Disorders and Risk of Mild Cognitive Impairment: A Nationwide Cohort Study

AIM: The role of mental disorders as risk factors for mild cognitive impairment (MCI) remains underexplored. Previous studies often focused narrowly on mental disorders, overlooking comorbidities among psychiatric patients. METHODS: Utilizing a nationwide cohort from 2009 to 2020, this study analyzed 2,717,131 individuals aged 40 years and above. Cox proportional hazards regression analysis was used to determine associations of mental disorders (depressive disorders, bipolar and related disorders, schizophrenia, anxiety disorders, insomnia) and the risk of MCI. RESULTS: Any mental disorder was associated with a 50% increased risk of MCI (HR: 1.50; 95% CI: 1.48-1.51), except for schizophrenia, which did not significantly alter the MCI risk (HR: 1.08; 95% CI 0.92-1.25). Individuals with a single diagnosis exhibited heightened MCI risk even when participants with multiple diagnoses were excluded (HR: 1.43; 95% CI: 1.41-1.45). CONCLUSIONS: Our findings advocate for a comprehensive approach addressing both disorder types and further cognitive deterioration.