Association Between Autoimmune Diseases, Treatments, and Dementia Risk: A Population-Based Case-Control Study From...

Objectives: This study aimed to assess the risk of dementia associated with specific autoimmune diseases and the impact of related pharmacologic treatments.

Methods: Patients 55 years or older diagnosed with dementia by neurologists or psychiatrists between 2010 and 2021 were identified using claims data from Taiwan's National Health Insurance program. We examined 22 autoimmune diseases for their associations with dementia, controlling for age, gender, urbanization level, and comorbidities.

Results: Dementia prevalence was higher among individuals with autoimmune diseases (10.5% in cases vs. 8.7% in comparisons). Thirteen autoimmune diseases were linked with an elevated dementia risk, particularly Behçet disease, multiple sclerosis, and systemic lupus erythematosus. Associations with vascular dementia were stronger than with Alzheimer disease. Although overall dementia risk was higher in women, no significant sex differences were observed for specific autoimmune diseases. Nonsteroidal anti-inflammatory drugs and corticosteroids did not significantly alter dementia risk among individuals with autoimmune diseases; however, immunosuppressants were associated with a reduced risk when used for more than 180 days.

Conclusions: Certain autoimmune diseases are significantly associated with an increased risk of dementia, particularly vascular dementia, highlighting the distinct role of inflammation. Effective prevention or treatment of autoimmune diseases may reduce dementia incidence by 0.8%. While immunosuppressants show potential for risk reduction, further prospective studies are needed to confirm this effect.