Try to approach her by urself or a person whom she trusts and try to talk her into visiting a doctor. Depending upon the local laws on forceful treatment of mentally ill people in ur country u can take future course of action.

This is the main issue here. Getting them the Doctor. They always refuse to meet the Doctor. And please do not jump to conclusions. Schizophrenia is a severe condition. Even depression can present with in controlled anger. Do you have a friend or a member of your family who is understanding of the situation and is closer to your mother? Like your uncle/aunt ( mother's brother or sister) Discuss the issue with them and take their help to convince your mother. The other option is to try home visits by a psychiatrist Meet a psychiatrist , discuss the issue , request him/her to visit the person at home. The diagnosis here is more important - is it anger or depression or something else. For this the doctor has to spend time with your mother for analysis. So consulting a psychiatrist is the only option you gabe