They're actually not that great for autism or ADHD. Keep in mind autism is a spectrum, meaning there is a wide range of issues and behaviors in kids with autism and the treatment of those behaviors have to be tailored individually. don't just hand your ASD kid a spinner and expect it to help any, or at all. Check with your kid's therapis first, or make sure its helping before letting them have it.

As for ADHD, it seems like it distracts them more than helps them concentrate. A lot of schools are banning them now. Parents were pushing the schools to allow them, but it looks like they were distracting the students more than helping, so the schools are pushing back on having what is basically a toy in class.

As an adult who likes to fidget, though, I love them, I have like three or four from a product testing company I work with and play with them all the time. But yeah, not great for kids.