You'll be happy to hear that, in recent years, the funding for Alzheimer's disease has boomed. My lab does a lot of research in AD and it is probably the fastest growing area of funding by NIH, from 600 million in 2015 to 2 billion this year[0]. Also, note Aging is another real growth area and a lot of Aging programs have AD/Dementia as a sub-focus. [0]: https://report.nih.gov/categorical_spending.aspx.

[Edit] from 1B to 4B if you count subcategories. Expect good things in the future.