Never go higher than 4.5 and thats usually for a larger man?

Less is more with this drug. It's not about taking it, it's about how your body kicks into gear when it wears off. The dose we take should wear off in 2-3 hours.

6mg might not be helping at all. Too high a dose. The least you can take, the better. Somewhere between 3 -4.5 is norm. Some take as little as 2.

He might do even better if you go back to the lower dose. At some point, it takes too long to get out of your system and your endorphins don't kick into overdrive like they should. It's not about what you take, the medication does nothing to help you, it's the sudden stop of the low dose overnight (usually) that is how it helps. Less is more.

It's curious you would see a specialist then not trust that the dose he prescribed is correct? I even wonder if 4.5 is high for a kid. (depends on his age and size.) 4.5 is really the highest one should be on. I've done so much research, seriously. There are tons of youtube vids. There used to be a Yahoo email group (don't know if it still exists) but there were some scientists on there that were on it and had amazing info. I picked brains for about a year before I went on.
Good luck.