Hi Anil Sagari, Welcome to Healthcare Magic and thanks for your question... Irrational fear, false beliefs, paranoid ideas, hearing voices, etc. are indicative of a type of psychiatric problem called psychosis . Now, psychosis can be due to various psychiatric illnesses or sometimes, due to medical causes also. Such psychiatric illnesses may include delusional disorder, severe depressive disorder, schizophrenia or late-stage dementia. Sometimes, sudden onset of psychosis in an elderly person can be due to a primary medical cause or a brain pathology. Certain medication like steroids, can also result in the development of psychotic symptoms. You need to take her to a psychiatrist who will be able to assess her in detail to determine the probable cause for these psychotic symptoms. If he suspects any medical cause or brain pathology, then she may have to undergo a few tests and maybe, a brain scan to detect any such causes. Treatment will also depend on the nature of the cause. For example, if she has a primary medical pathology, then that has to be treated first. If her psychosis is part of a depressive disorder, then she may require anti-depressants, in addition to the treatment for the psychotic symptoms. If it is part of a delusional disorder or schizophrenia, then anti-psychotic medication would be the primary line of treatment. All the best. - Dr. Jonas Sundarakumar Consultant Psychiatrist