What is the Official Definition of Insanity--in Cats?
In my opinion "special edition" isn't the most diplomatic way of describing a cat whose behavior and temperament aren't "normal".
Of course, the word normal needs to be in quotes because the truth is that there is no way to define a truly normal personality in any species. And there certainly is no official definition of insanity in cats.
There is no DSM-IV for cats (heck, we don't even have a DSM-I in veterinary medicine). Nonetheless, it is clear that cats and dogs can suffer from anxiety disorders (including separation anxiety in dogs), obsessive-compulsive behaviors (such as psychogenic alopecia in cats), impulse control problems, and a host of other psychogenic issues. (Vets use the term psychogenic in place of psychological.)
Brains are exceptionally complex organs. Hereditary traits and environmental conditions during development can lead to irregular brain circuitry and chemistry that are linked to behavioral or psychogenic issues in pets.
At this time, the field of veterinary behavior (which is the closest thing vets have to psychiatry or psychology) is still more or less in its infancy. But in due course I am confident we will make great strides towards understanding the basis of "abnormal" behaviors in pets. And maybe, some day, we will even have our own DSM.