PBS's Frontline did an investigative report on the over prescribing on Ritalin, Aderall, and other ADHD medication in the 1990s.
Doctors were given kickbacks by the pharmaceutical companies per child prescribed ADHD medication, regardless if they actually needed ADHD medication or not because of the huge heath insurance payouts received by the pharmaceutical companies
https://www.pbs.org/wgbh/pages/frontline/shows/medicating/interviews/diller.html
That ADHD is a subjective experience of a child and nobody knows how Ritalin works.
https://www.pbs.org/wgbh/pages/frontline/shows/medicating/backlash/lawsuits.html and that school districts have been sued over the mandatory prescribing of ADHD medication over the threat of child being expelled from the district if not prescribed the medication.