<human>:  I have a question about the MMSE, the Mini-Mental State Examination. When a person scores less than 20, what does that mean?
<bot>: A score of less than 20 is considered to be a sign of dementia. Dementia is a general term for a group of symptoms that can affect a person's memory, thinking, and behavior. Dementia can be caused by a number of different conditions, including Alzheimer's disease, vascular dementia, and Lewy body dementia.