This document discusses the relationship between alcoholism and dementia. It first provides statistics on rates of alcoholism and dementia worldwide. It then defines alcoholism and different types of dementia, and explores the physiological effects of alcoholism and Alzheimer's disease on the brain. Several studies are summarized that suggest light to moderate alcohol consumption may decrease dementia risk, while heavy drinking increases risk similarly to not drinking. The causes of brain atrophy differ between alcohol abuse and dementia. The conclusion is that more research is needed but alcoholism may increase dementia risk.