Mold in and of itself does not cause AD, but it is inflammatory, it is damaging, and it can cause serious brain fog.
I am fortunate that I am not one that is dealing with heavy mold exposure and toxicity, so this is not an area of expertise for me, but from my readings, I understand that the Impact of mycotoxins depend on:
1. Type and amount of mycotoxin exposure
2. Duration of exposure
3. Other toxins in the environment
4. Personal health profile
5. Diet. If mitochondria are weakened, they're more vulnerable and that can increase your susceptibility
For a better understanding, you may want to read the book "Head Strong" by Dave Asprey, he dealt with being overweight, heavy mold exposure, and traumatic brain injuries and "hacked" his way back to health and sharp thinking. He discusses this and provides strategies for others in that book.