In my experience, ADHD-ADHD friendships are pretty much the easiest ones to maintain. They’re the kind of friends who will drop off the face of the earth for six months (if you live far apart), pop up again suddenly, and it’s as if you only saw them yesterday.
As long as you generally treat each other with respect, I find that ADHD friends are a lot more understanding of issues that come with ADHD, because they know what it’s like. If you turn up 20 minutes late, they get it, they’re cool. You don’t call/forget to call? That’s cool, they forgot you were meant to call.
Best of all, you can be utterly mental around them, and they won’t think you’re a total freak- they’ll just be mental right back. They get your weird-ass humour, and they don’t get embarrassed when you do your Yoda impersonation at the store.
ADHD friends rock 😛