"A few individuals in government expressing concern can't equal the marketing power of large companies," said a former U.S. Drug Enforcement Agency official, regarding stimulants prescribed for children with "attention deficit hyperactivity disorder" (ADHD). Leading ADHD researcher Dr. William Pelham says McNeil Pharmaceuticals, which manufactures the stimulant Concerta, uses "misleading" marketing campaigns and has pressured Pelham to "water down" his writing. An ADHD advocacy group that receives pharmaceutical industry [3] funding, Children and Adults with Attention Deficit/Hyperactivity Disorder (CHADD), heavily edited an interview with Pelham in its magazine. Pelham says the incident exposed "major and undisclosed conflicts of interest with the pharmaceutical companies"; CHADD says they only removed "unsubstantiated claims."