The book was way scarier than I expected out of a middle grades book, but that’s just a testament to how well it’s written. I do know The Yellow Wallpaper, but find this version much more intense. My experiences aren’t the same (undiagnosed adhd and a weird heart thing instead of chronic fatigue), but are apparently similar enough that I related very strongly to a lot of the main character’s emotional journey. Maybe that’s why it felt so intense for me.