I know what you’re talking about. The term hyperfocus describes what can be a confusing aspect of ADHD: Sometimes kids who are usually easily distracted have trouble shifting their attention away from something they enjoy, like a TV show or video game.
When it comes to paying attention, there are three main difficulties for kids with ADHD:
Sustaining their attention
Choosing what’s important to pay attention to in a given moment
Shifting their attention from one thing to another
This helps explain why background noise can be so distracting when kids with ADHD are taking a test or doing homework. It also helps explain why these same kids have trouble tuning in to a family member who keeps calling their name while they’re playing a video game.
I should note, though, that even during these times of what seems like intense focus, a child with ADHD is not paying better attention than a child without ADHD.
Scientists have studied kids with ADHD while they play video games. While they may play the game as long as other kids do, kids with ADHD make more errors and do things like restart the game more often.
The ability to sustain or shift their attention isn’t conscious or in their control. That’s why telling a child with ADHD to concentrate harder or to stop daydreaming is like asking a child who’s nearsighted to try to see farther without glasses.