Dementia is one of neurodegenerative disease without preventive medicine currently. Dextromethorphan (DXM) has been reported to reduce neuronal damage and neurodegeneration in animal and human models. The effect of DXM on the dementia has not been fully examined. We examined the medical records over 40 years old in Taiwan's National Health Insurance Research Database between 2000 and 2015 to establish matched cohorts. We used a Cox regression hazard model to identify risk factors of dementia during 16 years of follow-up, and the results indicate that a significantly lower percentage of subjects with DXM use (P < .001) developed dementia compared with those without DXM use (11.38%, 4541/39 895 vs 18.66%, 29 785/159 580). After adjustment for age and other variables [adjusted hazard ratio: .567 (95% confidence interval: .413-.678, P < .001)], this study also demonstrated that DXM use appeared to reduce the risk of developing dementia. DXM use may potentially provide a protective effect against dementia.
Keywords: Alzheimer disease; cognition decline; dementia; dextromethorphan.