The annual budget of NINDS is around $1.3bln and NIA $1.1bln, so a total investment of $1.3 for AD is actually pretty damn high, relatively speaking. I'm not sure what other institutes support AD research, but I imagine those are the two primary ones.

A doubling of the total NIH budget would be a very good thing, but it should come with structural reforms, as well. Primarily, the indirect cost model, which basically uses NIH money to fund universities, needs to go ASAP. Our institution (not a university, actually) has an indirect rate of I believe 48.5%. For the uninitiated, that means that one third of all dollars that I get from the feds to support my research goes to the administration of the institution. One hopes that those monies support paying the mortgage, paying the administrators, and paying the utilities, but generally, that money can go into the general fund. So, at a university it's probably paying some instructors' salaries and for building remodels. That's why if you don't get a grant, you're out on your ass. The bureaucracy is gigantic, and getting bigger all the time. The system feels soviet in its proportions and complexity at times.

Also, the previous time that the NIH budget was doubled, lots of the money was used to fund more and more graduate students, many of whom are fucked right now because of the lack of available jobs.

For these reasons, I'm all for increasing the budget, but also for reforming the NIH, turning it into a research supporting organization, instead of club where old faculty and administrators give each other reach arounds to the tune of billions of dollars.