No bargaining works with him. In that case, he starts shouting, abusing, stop taking food at home etc.
Sadly, and regardless of your sons condition, you sound to be locked in a very negative spiral that he is "manipulating" to keep his status quo. Strops and tantrums cannot last forever; although when I am not the one living with them, that is easy for me to say! I would of course be happy to advise you further on firm, but consistent methods but this is essentially just that: the approach would need to involve sitting him down, telling him that things will change and what you expect (for example, take you r meds when under my roof or you lose the computer, or you dont get the new gadget - in general positive incentives ALWAYS work better than negative punishments as motivators). He then WILL rebel, he WILL push the boundaries and he MAY even become "nasty" as he goes through his last phases of trying to keep his status quo. You would obviously need supreme levels of support from other members of family and friends for this ... is that something that you can rely upon?
Thank you Rob.
But one last query. Yeasterday I only (as I can not take my son, he is against it) visited one psychiatrist, he pescribed 'Olimelt2.5mg(Olanzapine). What I know through net that this is used for treating Schizoprania. Please advice.
I'll wait for this answer and then give feedback.
I received a good and worthy guidance from you.
Once again, thanks and regards XXXXX XXXXX