The sale of Ritalinâ increased 500% between 1990 and 1999 in the United States. The sale of drugs containing amphetamine (Adderallâ and Dexedrineâ) increased 2000% in the same time (Woodworth). The United States produces and consumes 85% of the world’s methylphenidate (commonly known as Ritalinâ), according to the United Nations (INCB Report, 1998 ( Read more... )