Not yet; the drugs are still so new that.... I think Aricept will be the first one to go off patent protection, but it isn't yet. I don't have the dates for the other ones.
We really have only four drugs that are available, and they're really only available in the mild and moderate stages of the disease. After that time they become ineffective and really don't work very well, so people go off them. The decline is then quite steep once they go off those medications.
On the cost to the health care system, I would just also comment that there is a huge cost to the health care system of not making sure that we have investment in research. I talked a little bit about the investment that's needed in brain research to treat all the many neurological conditions for which we have really no treatment and no cure. We know now that the cost to our society of people having Alzheimer's disease is $15 billion a year. Within a generation, or by 2038, that cost will balloon to $153 billion if we do nothing.
So there's a cost to doing nothing as well.