My Dad smoked for 50 years, from the time he was 17 until he was around 67. He tried to quit on numerous occasions over the years; finally did quit cold turkey about 15 years ago. I often wonder if smoking over an extended period like that can be a factor in not so much the cause of Alzheimer's or other dementias, but in the progression of the disease. Or are people who may somehow be genetically prone to Alzheimer's also prone to smoke? Can the 'symptoms' of smoking -- restlessness, the need to have the cigarette in one's hand, etc. -- mask the beginnings of dementia?