Well, there is partial truth to this. Diagnosing especially preteens with mental health conditions almost always needs an asterisk, their brains are still heavily developing.

Remember that we know of no reliable genetic / physiological markers for ADHD, so when doctors diagnose it, they’re really just saying that the amount of symptoms seems to be severe enough. Some kids are just naturally more energetic, intelligent, etc. and may appear like they have ADHD, but when they develop into adults that might not actually be the case.

If anything, it’s more like 1/3 of kids were misdiagnosed as having ADHD, so they “grew” out of it because they didn’t really have it. It’s a lot less likely for an adult to be misdiagnosed because their brains aren’t changing.

Try to frame it like it’s exciting, not a failure. It’s fun that you have so many more books you want to read!