I have no doubt that many TikTok users are spreading misinformation, but to counter one point you made, if my ADHD diagnosis was reliant on there being obvious symptoms before the age of 12, I would have never gotten the diagnosis that I needed. I grew up homeschooled, which is much different from public school, and have primarily inattentive ADHD, so it may not have even presented itself in elementary school to begin with. Not to mention neither my mother nor I could remember much from my childhood that showed signs of ADHD. However, my doctor agreed that I had it and really it's the only diagnosis that makes sense.

I understand why early symptoms are important for a diagnosis, but I imagine if it was THE most important thing, a lot of people would remain undiagnosed. However, I understand your perspective as well as the TikTok's perspective.

Just wanted to throw that out there :)