’He’s completely addled, you know — still thinks he’s a teapot.
…raising his voice a little more, his grey eyes glittering malevolently in Harry and Ron’s direction, ’if it’s a question of influence with the Ministry, I don’t think they’ve got much chance… from what my father says, they’ve been looking for an excuse to sack Arthur Weasley for years… and as for Potter… my father says it’s a matter of time before the Ministry has him carted off to St Mungo’s… apparently they’ve got a special ward for people whose brains have been addled by magic.
There are no more uses of "addle" in the book.
Show samples from other sources
But she counted and counted till she got that addled she’d start to count in the basket for a spoon sometimes; and so, three times they come out right, and three times they come out wrong.
Mark Twain -- The Adventures of Huckleberry Finn
Although her relations with Atticus and Jem had reached their lowest ebb ("You’re downright addled these days, Jean Louise," her father had said.