I've found chess very good for this. I can easily play for 3-6 hours in one session while getting completely in flow / losing track of time. My wife is not as

I've found chess very good for this. I can easily play for 3-6 hours in one session while getting completely in flow / losing track of time. My wife is not as much a fan of this... Canadian chess grandmaster Eric Hansen used chess to help with his ADHD as a child.