Under the ADA, employees have the right to choose whether to disclose their disability. I can't accommodate them without disclosure. However, I can create a safe environment, explicitly making it clear we're open to such diversity. Letting your employees know you are open to accommodation, and open to diversity in general, are factors in their decision to disclose.
My blunt instrument hiring modality has been a very cruel, old fashioned view of alpha employees and their lessers. Having a child with learning disabilities, AND having very capable, essential staff with learning disabilities, discovered only after many years, has made me painfully aware of my error in understanding. I would be discounting some very capable, creative people, if I kept my outdated understanding.
As small business owners, we generally feel that we're too small for specialization and thus we don't want to think about accommodation. It's a kind of don't ask, don't tell. I think we're missing out on a lot of very good people who just happen to process the world differently. To be an owner you need to be good at everything (or hire for your shortcomings), but I think it's wrong to expect that from every employee. Also look for areas in which they shine brighter than the average employee. My son has difficulty reading, but he has an iron clad memory and a college level vocabulary.
I have nine people on staff now, which statistically means one probably has a learning disability. Like all staff before them, it is pretty well hidden, since we don't make any effort to discuss learning disabilities with new hires or staff members. Let your employees and potential new hires know you are accepting of diversity of all sorts, including cognitive differences. My bet is like being open with other sorts of diversity, you'll unlock a lot of human potential.
Anyway, I'm no expert on this topic, just a business owner and father.