[ CW ] Show a character suffering from a mental disorder without naming it .

Mrs. Petrie informed us that today was a very important lesson, because all the information she was going to cover would be on The Test. The capital letters shone royal blue, a more vibrant shade than the lower case t. It made me focus, but that did n't last long, as usual. But it's not my fault, really. I've tried to tell her that it's when she uses the chalk, I ca n't concentrate, but she ignores me every time and does it anyway. 
 
 And I'll try to dodge that gentle kneading pressure that floats to my seat from the intersection of chalk and chalkboard -- I'll squirm in my seat, slumping low in my seat while shifting my shoulders away from Mrs. Petrie's rapidly moving hand -- but it finds me every time. Each flicker of her wrist sends another thrum of relaxation along my nerve endings, like when Mom rubs my shoulders and tells me it's okay. When she drags it along the board for too long, the other kids groan and complain, but that's when the pressure hits right between my shoulder blades and feels the best. 
 
 And before you know it, the sound of her writing has felt so good, I've gone to sleep. 
 
 [ Edit: I remembered after the fact that this is about a neurological phenomenon and not a mental disorder... since it's still about how the character's brain interprets things in a way that causes problems with day-to-day life, I'm leaving it. ]
