Some food for thought:

(From Wikipedia.org); more references can be found here

Attention-Deficit Hyperactivity Disorder (ADHD) is usually considered to be a neurobehavioral[1] developmental disorder.[2] It affects about 3-5% of school aged children[3] with symptoms starting before seven years of age. It is characterized by a persistent pattern of impulsiveness and inattention, with or without a component of hyperactivity.[4] ADHD occurs twice as commonly in boys as in girls.[5] ADHD is generally a chronic[6] disorder with 10 to 40% of individuals diagnosed in childhood continuing to meet diagnostic criteria in adulthood.[7][8] As they mature, adolescents and adults with ADHD are likely to develop coping mechanisms to compensate for their impairment.[9]

Though previously regarded as a childhood diagnosis ADHD can continue throughout adulthood.[10] ADHD has a strong genetic component.[11]

The most common symptoms of ADHD are[24][25]:

* Impulsiveness: acting before thinking of consequences, jumping from one activity to another, disorganization, tendency to interrupt during conversations.[24]
* Hyperactivity: restlessness, often characterized by an inability to sit still, fidgeting, squirminess, climbing on things, restless sleep.[24]
* Inattention: easily distracted, zoning out, not finishing work, difficulty listening.[24]

Not knowing Donny in person I cannot be 100% sure that this is his problem, but sure as hell he HAS a problem that needs treatment.
I don't want him to leave this Forum, but the way he is now he can give this Forum only 20% (maybe) of what he has to offer; the remaining 80% of the time in my opinion he is just making a fool of himself and is losing all his credibility, like others have remarked, and this is really a sad thing.