Not a doctor so I can't say if it's a disorder or anything. I personally have a hard time reading things that do not interest me. I wish I was the type of person to sit down with a non fiction book and learn something, but that is just not my genre. Even when I have an educational book on a subject I enjoy, I don't read cover to cover. I bounce around and read parts that pertain to what I am interested in the moment. Give me a dystopian sci fi novel and I will DEVOUR it. Have your tried 'Parable of the Sower' by Octavia Butler. That's the book that revived my passion for reading after a lengthy literature break.