It's important to remember, that even though the popular vote has not been particularly close in several recent presidential elections, the actual outcome depended on just a few thousand voters, in a few states.

I think that in 2016, if voters had understood that Trump wasn't just "acting" but really couldn't control his line of thought, his impulsivity, or his hyperactivity, due to his ADHD, that this could have deterred enough people from voting for him that it would have made a difference.

But separate from electoral outcomes, having information about what conditions our candidates or officials have can help us make more sense of what is going on in a turbulent and strange world, which I believe is a benefit.