Tumblr post I wrote about the current research surrounding this topic:
https://www.tumblr.com/astralarya/736730872361910272/overwhelming-evidence-for-a-major-role-for-herpes

"causative factor" meaning that it can have downstream effects leading to dementia, or that most dementia is caused by it?

The former, although it'd have to be at least, let's say, >2% of dementia cases, so that a .00001% increase doesn't count. (obviously I didn't think too hard about this market. feedback on better criteria welcome!)