Hi,
I think that 300mg of the XL is the max dose according to my son's doc. Last year we had him on 300 mg and when that did not give us the results we were looking for we added Ritalin LA (2omg then 30mg). That was a good combo for my son but created tics. I felt when my son was on wellbutrin alone his personality was very flat. Over the summer we took him off of the wellbutrin but stayed with the Ritlalin LA. It still was not right and we have added Zoloft (before Zoloft we tried Tenex, no improvement). I have not decided if the Zoloft is good or not. We changed from the Ritalin LA to Vvanyse a couple of days ago because we needed longer coverage. I don't know if my information helped or not. Oh and my son is 11 next month and tall but thin.