My mother began having paranoia about a year ago. She thinks everyone is out to get her. She thought her work agency was canceling her hair appointments and intercepting her mail just to make her life miserable. She thinks people are plotting against her at social events and now she thinks her own children are out to get her. No matter what we say she won't believe us. She is fully functional living with my dad and doing day to day activities but her mind is a mess. It's making me and my siblings very sad and sometimes angry. What should I do if she refuses to go to a doctor or take meds? Could it be dementia? I'm even worried she might have a brain tumor. Any advice?