Suggest Treatment For Autism

I work in a special education setting. One student is a 13 year old with autism and ADHD. He has recently become obsessed about another student, talking about the child all the time and stating that this child makes him so mad he goes home and screams in his pillow. If the other child wears the same shoes, this can set him off, stating that the child will soon be wearing all the same clothing as he. He whines frequently, talks a great deal, feels that everyone is treated better than he is, will be very disrespectful and will state when angry that he is going to sit in the storage closet. One of his peers is able to calm him down and get him to do some work. There have been times when his behavior is not nearly as bad. His mother states that he is on vyvanse and Zoloft. He has been on this for years so the mother does not think it is his meds; I asked her to please talk to her doctor because he has also made threats to the child. Could meds be responsible.