My Dad Has Just Been Diagnosed With Alzheimer’s

My dad has just been diagnosed with Alzheimer’s.  How long do Alzheimer’s patients live and what can we expect as they progress through the disease?    
Alzheimer’s dementia is a progressive, incurable, terminal disease which is becoming more common, mostly because we are living longer.  It is a Neuro-Cognitive Disease – meaning specific areas of the brain are damaged and result in significant changes in thinking and behavior.
Dementia is a general term which includes several types:   Alzheimer’s is the most common (65%); Vascular type (due to mini-strokes/strokes) is about 15%; Lewy-Body type accounts for 10-15%; with the remainder caused by alcoholism, Parkinson’s disease, etc.
What can we expect?  Their progressive loss of social skills and personality is described using the Functional Assessment Stages [F.A.S.T.]— “1” (normal) through to Stage “7” (end-stage).  Most ‘problem’ behaviors begin in Stage 5, with delusions, acting out, hoarding, wandering, increasing repetition of questions, getting lost.  In Stage 6, they begin losing their ability to care for themselves [dressing, bathing, toileting, incontinence of bladder and bowels].
Finally, in Stage 7, they go from having limited conversations to not talking at all, and will eventually become bedbound, requiring total care, no longer knowing family members.
Because of this loss of personality and the increasing behavior problems, the stress on families caring for dementia patients is incredible:  many have said the disease is worse than cancer.  [That’s why more patients have Advance Directives stating to NOT prolong their life if they develop dementia.]
I believe many dementia patients have pain that they won’t or cannot admit to; and this pain  causes their agitation.  Therefore, it’s important they receive pain medications.  Most studies now show anti-psychotic drugs rarely help; whereas, pain drugs, such as morphine, has allowed them (and their families) to enjoy life better.
How long do they live?  The average life expectancy is 4.5 years although some live beyond 10 years.  Once they reach Stage 7’c’ (can’t get out of bed without assistance and can’t carry on a sensible conversation), the average life expectancy is only another four months.  However, if their decline does not follow the Stages in order (1 through 7), they can live another year (or longer).
For patients to be eligible for hospice, they must be in Stage 7(c) and also have weight loss or other significant problems.