Halif you may have adult ADH. It may be worthwhile getting checked out by a Dr. I have ADH and take medication (when I feel I need it, it's moderate ADH.) I don't take ritalin or dex, although I have in the past. Using a RC to treat a medical condition is to much of an unknown quantity. I am curious to see if any animal studies have been undertaken, if the animals studied compulsively redose, mg per kg for fatal arrythmias, coordination tests etc. Thanks for the info on methylphenidate pharmacodynamics Mr. Blonde, very interesting.