Back in 2004 I did a thesis on methylphenidate and the overdiagnosis of ADHD. What happens is that kids take this drug and need to take other medication to go to sleep and you end up with kids on ritalin, and prozac and and other prescription depressants to help them sleep because the ritalin keeps them awake at night. Then all the meds these kids are on start interacting in bad ways (kids start hearing voices telling them to hurt others and themselves), so they end up on anti-psychotic drugs.
It helps not to stuff kids with sugary crap but get them to unload energy in sports, and keep them busy with work and hobbies.