If a drug like vyvanse
was started, it must have been with a purpose. This drug has very clear indications but in your child there is no diagnosis. Your child's treatment history needs a thorough recheck and why exactly the drug was started.
kindly provide more information on his behavioral pattern. Has he been doing well in school or lacks in specific subjects ?
He must be having school related problems. He could be facing some embarrassing moments at school and might not be discussing the same with you.
Kindly get in touch with the school teacher also.