"Recently, Chermá et al reported a large variation in the optimal treatment dose of 59 patients with ADHD; however, blood sample analysis revealed that the median daily dose per body weight [for Ritalin] was similar (~1.0 mg/kg)."
Interesting!
I have a (gradually improving) obesity problem and I currently weigh about 130 kg.
This would explain why daily doses of about 100-100 mg seem to work best for me. I'm going to have to let the psychiatrist know.