Dear Welcome to HCM We understand your concerns I went through your details. I suggest you not to worry much. From the description, your son might have come across some negative happening (type of shock) while at his hostel. That happening changed his thinking pattern and then he was habituated with the new habit. We need to understand what happened at the hostel. Then change his pattern of thoughts and habits. Programing or tuning his neural network is what the treatment is all about. A trained psychologist can do the treatment with the help of psychotherapy techniques. If you require more of my help in this aspect, Please post a direct question to me in this website. Make sure that you include every minute details possible. I shall prescribe the needed psychotherapy techniques which should help you cure your condition further. Hope this answers your query. Available for further clarifications. Good luck.