Hi, I do appreciate your concern for your cousin. From what you have mentioned, it seems that your cousin is having symptoms suggestive of a delusion of persecution. It is a condition in which a person starts feeling that people are trying to harm him. It is part of a psychotic condition and can be due to a primary psychotic condition like schizophrenia or may be secondary to depression. I would suggest that you seek a psychiatric evaluation of your cousin and initiate treatment. He will need treatment with anti-psychotics like olanzapine. An anti-depressant would also be required if he has an underlying depression. I do hope that you found the information helpful. Best wishes.