Edit: Please read carefully. The point of this post is NOT to suggest that there is a correlation between ADHD and certain MB types; it's the opposite, that there probably isn't one.
There've been several threads about this at once and a few others in the past, so to hopefully put it to bed, here's what happened when over 300 people on an ADHD support forum took the humanmetrics test. As you can see, every type is represented, and in the same broad proportions as are found on every other Internet forum I've cared to investigate. As usual, INXP was the most common, ESXJ the least common.
ADHD MBTI Poll
It stands to reason to me that different types will manifest hyperactivity, impulsivity and/or inattention in different ways, some in less stereotypical or socially isolating ways and some perhaps more likely to be diagnosed later in life than others as a result, but all experiencing those three non-MBTI related symptoms to a degree that is significantly impairing and/or distressing.
Edit: Chapter six of this book (read it here) explains more and mentions a study that also suggested ADHD is not the same thing as certain MB types, and in fact found a slight negative correlation between ADHD and perceived 'ADHD-like' MB types. Scroll down about an inch to read it.