My dad was diagnosed with mixed Alzheimer's and vascular dementia a year ago. He lives on his own and is in denial and gets increasingly angry if you try to address the subject. At first I noticed that he would mix up events from the past or confuse fictional TV with reality. He had good days and bad days. Unfortunately I feel he has become more delusional over the past few months and is increasingly becoming anxious about events that have not happened. Most recently he believes that the police are outside his accommodation and are checking people for passports and papers when they either enter or leave. He feels that he is locked in and can't leave and feels that he is under surveillance. He appears genuinely scared. I don't know how to react for the best. Do I put him right or do I just go along with it? I tried trying to calm him down over the phone but he gets increasingly angry and just shouts that he knows I would react like that! I'm confused and at a loss of what to do.... Any thoughts?