effect of the stimulants appears to be an improvement in classroom manageability rather than academic performance". In 1991, Barkley noted that "Psychostimulant medications (e.g., Ritalin) are highly effective treatments for the symptomatic management of children with ADHD as they can enhance significantly their attention span, impulse control, academic performance, and peer relationships". In response to critics who point to countries with lower rates of diagnoses and medication of children for ADHD, Barkley said, "So what? We do not let the rest of the world set our standards of care when we do more research on childhood disorders--specifically ADHD--than other countries combined?". Barkley believes that drugs such as Adderall, Ritalin and Concerta should be downgraded to schedule III. During an interview in 2001, Barkley said that "All of the research we have indicates that these drugs are some of the safest that we employ in the field of psychiatry and psychology. That's not to say that we know everything about them. But we know a lot more than we know about cough medicines and Tylenol and aspirins and other things that children swill whenever they come down with a common cold. Nobody asks those questions about those over-the-counter medications, yet we know substantially less about them". Barkley has compared “ADHD” to a physical handicap, with Ritalin being the equivalent of a wheelchair. On 16 November 1998 he said that "Ritalin will be ranked as one of the leading developments in this century for helping individuals". In 1999 Barkley said "Once convinced of an ADHD diagnosis there is no compelling reason (For someone diagnosed with ADHD) to avoid Ritalin". Consultant He has been a paid consultant, for pharmaceutical companies including Eli Lilly, McNeil, Janssen-Orth, Janssen-Cilag, Novartis, Shire, Takeda pharmaceuticals, and Theravance. Books Attention Deficit Hyperactivity Disorder: A Handbook for Diagnosis and Treatment.4th ed. New York: Guilford Press, 2015. . ADHD and the Nature of Self Control. New York: Guilford Press, 1997. . Taking Charge of ADHD: The Complete, Authoritative Guide for Parents. New York: Guilford Press, (3rd ed.) 2013. . With Kevin R Murphy and Mariellen Fischer. ADHD in Adults: What the Science Says. New York: Guilford Press, 2008. . Attention Deficit Hyperactivity Disorder in Adults: The Latest Assessment and Treatment Strategies. Sudbury, MA: Jones and Bartlett, 2010. . Taking Charge of Adult ADHD. New York: Guilford Press, 2010. . Executive Functions: What They Are, How They Work, and Why They Evolved.