Just as a point of balance: adult onset ADHD, while possible, is quite rare. Many other more common disorders, such as anxiety and depression, will share the same symptoms as ADHD.
Yes most everyone says the symptoms need to be present in childhood as well. But apparently the structure of school and just being a little smart can mask the performance symptoms in childhood. Then once the structure is gone in adulthood and life becomes much harder and more complex, the big symptoms start to show up.
Not to be pedantic, but just because symptoms are masked does not mean they are/were not present. I think the differentiator is whether one had symptoms to mask or not in the first place.
I masked some of my symptoms as a child, was diagnosed as an adult, etc., but the symptoms were always there despite my prior ability to function around them.
