I've decided to stay at 36mg because I felt more nausea on 54mg. This is unfortunate because I felt more productive on 54mg. Although, that could be coincidence. And the difference wasn't drastic.
But even on 36mg, I feel nausea sometimes. I feel slightly nauseous now. I need to figure out what contributes to it or why it happens at all. Google hasn't helped me so far, but I'll look again.
Overall, though, this week at work I was very productive, so I'm glad Concerta seems to be working.
Oh, and I didn't drink as much caffeine this week, which is good for my heart! And no noticeable withdrawal.
Finally, I should note that I slept a fair amount this week, more on average than last week and more consistent.