Kindergarten (and school in general) anxiety is relatively normal (or so the experts say) because of the transition from preschool to the bigger grade school. Starting kindergarten is a major developmental milestone and for many parents and children, a rites of passage.
Unfortunately, many children, including my son, felt anxious over this huge transition. I don't think it is related at all to his adoption but to his issues with transitions instead.
He did a great job the first week of school because he was very excited about his new school, riding the bus, and meeting his new teacher and friends. However, once he learned what the new expectations were for him (and he learned this fairly quickly) he shut down.
We learned a lot about him in the first two weeks of his kindergarten year and I have to say that it has was a fabulous learning experience for us. Not only did we learned that transitions like that one cause him so much anxiety that it actually causes him medical problems (thus the Prevacid) but we also learned that when people expect him to behave a certain way he knows this and will act the opposite to try to get out of the situation.
I have seen him act this way before, pushing me away and trying to act bad so that I would leave him alone or push him away in return but I have never seen him do it to other people (this was, of course, adoption related). Because he is verbal now he was actually able to tell me that he was mad at his teacher because she tries to make him do things he doesn't want to do. So, he was trying to act bad so that he could go back to his old, "little people" class where they had fun all day.
The logic of a five year old really gets ya, huh?
His teacher was a great help. She was extremely patient with him and listened to my suggestions. Trying not to be overbearing is hard though...I don't want to tell her how to do her job, I just wanted to help make his adjustment easier.