I think it's in the nature of kittens to have short attention spans.
So I wouldn't call it a "disorder". Smudge was very restless and
constantly moving from one thing to the next when she was a kitten.
She could never sit still - it used to drive me nuts. I was afraid
she'd always be like that, never settling down in your lap for more
than 30 seconds. I thought maybe it was because she was very smart,
and got bored easily. (She is the smartest of my 3.) So, maybe you
just have a genius cat on your hands! :) Fortunately, Smudge has
settled down a lot, so your kitten might, too.

I've heard the viewpoint that people who have ADD don't really have
a disorder, but merely have a different way of operating in the world.
It's just that, the way modern society works, it's better if you can
focus on one thing for long periods of time. If you can't, it's harder
to fit in with the work environment and other human activities.

I remember reading about a theory that what we call ADD is really
just a genetic variation in the type of brain organization, left over
from when all humans were hunter-gatherers. To be a successful hunter,
you have to be constantly scanning the environment for prey, and alert
to movement coming from any direction. So being easily distractable is
a benefit in that case. But then when humans started to settle down,
develop agriculture, and build civilizations, it started to be advantageous
to have the kind of mind that can focus well on one thing at a time.
But most traits don't change completely throughout an evolving population
overnight, not to mention that many people remained hunter-gatherers
while others settled in cities (there are still hunter-gatherers today),
so the "ADD" trait would still have a good reason to be kept in the gene
pool.

Bringing it back to cats, I would think that, being hunters, they would
benefit well from having ADD brains. My small sample bears out this
theory - Smudge is (or was, as a kitten) very distractable, and she's
a good hunter. Roxy is extremely patient and can focus on one thing
forever - in fact, she seems to be meditating a lot of the time - but
she's useless as a hunter. Licky's still pretty young and distractable,
and he's a good hunter too.

I expect that others will have contradictory examples to offer. But I
think it's an interesting theory.

Joyce