also get notions.

We as parents have to be careful to not attribute all behaviors to
the ADHD--this is really a downside to labels. (My son was diagnosed at age 9 with ADHD and took stimulants for almost 5 yrs).

My son wanted BOOTS... neither of us wear boots!
He still wears them.(at 27)

ADD stimulants can make kids strident. But if your son is okay in other ways, I think he is just expressing his growing self.
Parents have to be very careful to separate out the LABEL and allow their children to grow into what they want to be.

To this day my son is jeans, T-shirts, and boots. (Sometimes he wears regular footwear). Luckily for him his job has no
dress code and computer people all wear jeans and Tshirts!
The money he saves allows him to buy the techie phones and doodads he likes! LOL

Nine years old is early, but hey, kids mature earlier these days with all the media and other things. My son started puberty at 11 which was young for males. So please just consider this a part of "growing up'.