Evanna Lynch (Luna Lovegood) was anorexic already at an age of 11. She wrote a letter to J. K. Rowling and told her, that the stories gave her hope, especially Luna Lovegood. Rowling wrote back and assured Lynch, she could have the role of Luna, if she fought the anorexia. Lynch managed to recover and really got the role.

A proposed title for the american version of Philosopher's Stone was Harry Potter and the school of magic.