would like to ask what causes panic attack actually? depression? misuse of medicine?

my mom was diagnosed having schizophrenia last 2 months. then doctor prescribed her with lorazepam 1mg on daily basis.

soon after she has been discharged from hospital, she is so dependent on lorazepam to the extent that she will have panic attack every 2 days if she doesnt take FULL lorazepam 1mg for a day.

very headache to see my mom having panic attack symptoms, and these symptoms can last more than 8 hours sometimes

i actually brought her to see doctor, doctor just changed the medicine to T.Xanax 0.5mg. however, we couldn't get the medicine because of no stock in hospital. so now my mom is still taking lorazepam 1mg.

yes she does, she is taking Tolanz (Olanzapine) 10mg every day.
now she has reduced the intake of lorazepam to half a tablet per day. i keep telling her that she must do something to make herself feel happy and distracted so she won't have time to worry that panic attack will kick in again.

she is treated in UMMC by a medical officer. and i dislike the medical officer after few appointments due to his attitude of treating my mom. this medical officer is not a serious doctor.

im also looking for a good psychiatrist. my friends around me told me that i need to go to private specialist if i want to get the experienced one (going govt hospital may take time to queue)