About 85 to 90 percent of all prescriptions for methylphenidate in the United States are written for young children and adolescents for the treatment of ADHD. Methylphenidate is available as the brand name product, Ritalin, and as a generic product. The use of methylphenidate in the United States has increased dramatically in recent years, and this increase contrasts sharply with medical practice trends in the rest of the world. According to 1993 United Nations statistics on psychotropic drugs, the United States produces and consumes five times more methylphenidate than the rest of the world combined. Internationally, methylphenidate is listed in Schedule II of the Convention on Psychotropic Substances of 1971, along with amphetamine and methamphetamine. Under treaty obligations, the United States must provide data to the United Nations International Narcotics Control Board on the production, distribution, and consumption of methylphenidate. Because the United States prescribes methylphenidate in significant volume, support and advisory groups need to play an important role in the distribution of information about ADHD and its treatment. Of particular concern is that ADHD literature prepared for public consumption does not address the potential or actual abuse of methylphenidate. Instead, methylphenidate is routinely portrayed as a benign, mild substance that is not associated with abuse or serious side effects. In reality, however, the scientific literature indicates that methylphenidate shares the same abuse potential as other Schedule II stimulants. Further, case reports document that methylphenidate abuse can lead to tolerance and severe psychological dependence. Industry practices associated with the manufacture and distribution of methylphenidate are examined, along with current public health concerns over the drug. 112 references, 67 footnotes, 2 tables, and 2 figures