However, he refuses to believe he has it and refuses to take medicine. I have snuck Vyvance into his morning breakfast drink, on the days he has several tests at school.,His focus is much better and he gets more done. He has been very irritable after it wears off, probably because he has not adjusted to the medicine. Should I continue sneaking it in his drink every day? How do I tell him and try and get him to take it independently???