How Long Do We Need To Continue With Olanzapine For Depression?

Hello doctor, my sister is suffering from many symptoms like suspiciousness,she is a very dependent kingd of person and unluckily her husband had an accident-helicopter crash after which she started developing ?depression,?schizophrenic kind of symptoms .My parents are looking after her children and her.She was kept on Aripiprazole,Pimozide and Parkin.But, since my parents were out, she has stopped her medications.Again she started developing suspiciousness that people are trying to conspire against our family, and trying to irritate her,she is also suffering from insomnia.she has stopped her medications.iam planning to take her to psychiatrist again ,but after my parents arrive.now after consultation with my freind who is a doctor we have added T. olanzapine.for how long do we need to continue olanzapine,can u plaease suggest.