Delusion and disorganised. Normally?

My mother since last few months has started talking about someone watching her activities as well as influencing whatever is going on in and around the country and world. She doesn't sleep anymore on the bed saying someone tried to give electric shock through the same. She wraps a towel around her head for no apparent reason and pulls up shirt and sweater even if not cold or chilly. Rest of the daily routines are not hampered. She cooks her own food and for my dad. Some of the Psychiatrist we visited are suggesting medicines. But I doubt how mom will take such medicines when she herself prepared the food and will consider any meds as an act of that unknown entity trying to overpower or monitor her? Can psychologist help in any manner in convincing her to take the medicines (if they are a necessity) in her treatment. Could there be any other physiological causes that could trigger such symptoms? How can she treat herself without the need for any assistance and function normally?