[Aramgutang]

Ritalin displays no significant activity on 5HT receptors, in contrast to dexamphetamine, which does have significant serotogenic effects.

Yes, they are not related, but both are taken for their dopaminergic effects, though they achieve this by different methods (reuptake inhibitor vs agonist).

Generally, in the course of treatment for ADHD, patients will get to try both to see which one they respond to better. They often exhibit strong preference for one over the other (personally, dex does nothing for me, even at recreational doses of 50mg).

Their risk profiles are very similar, and one cannot be said to have "less side effects", unless referring to a specific individual's response.