I have been screened a few times for ADHD and each time was found to obviously have it.
Ritalin does not make me feel calmer. I have been told by those close to me that there are externally visible improvements in my behavior. At doses to reach that effect, it also impacts my sleep quality enough that I don't take it.
Adderall causes mild symptoms of psychosis and mania before it has any theraputic effect.
Dexmethylphenidate (aka Focalin) has identical theraputic effects to ritalin, but slightly reduced side-effects.