Well, yes, but that's going back awfully far - back to the mid-'60's or so. The Joker has been acknowledged as completely bonkers at LEAST since then - longer, if you count the first few stories he was in, where Batman references his madness a number of times. The only Batman villain today who has anything close to an 'outre obsessive compulsive disorder' would be the Riddler, with possibly the Mad Hatter coming in a close second. Most of the rest of them are out-and-out nuts.