My Dad was diagnosed with AD late last year - the usual symptoms of memory loss and some confusion. He started a course of Aricept which improved things a lot - particularly the late-night confusion (he would fall asleep in the evening and wake up insisting it was the next day and time to take his tablets, or think that things he'd heard from the TV while asleep meant someone was there). However, a new problem has surfaced. About eight months ago he started worrying about our neighbour's guttering and the way it no longer connected to ours properly (their fault) lead to their front garden flooding in heavy rain. He started worrying that they would "blame us" This worry has been getting worse and worse, to the point that he thinks the neighbour is plotting against him and is sneaking out late at night and damaging our guttering/paintwork/garden wall as some sort of revenge (!). Every day he insists that someone has "had a go" at our guttering/wall etc and keeps on making me go outside to see the "damage". Yesterday he would not speak to me about it in our hall as he thought the neighbour has a "listener" on the wall. I even went so far as to take photos of the house while the neighbour was on holiday so that when "new damage" appeared I could show that nothing had changed...but of course this had no effect. He also knows that the neighbour is a Mormon and suddenly Mormons are responsible for all the evils in the world. Sadly when talking to the neighbour (which he does quite happily!) he made a passing comment about living until he was 100 and the neighbour made a joke about "have to do something about that". So he came in and said "if I die suddenly you will have to have it investigated"! It's making me and Mum's life a misery. He's seeing his GP next week and Mum is going in first (on a pretence) to bring up the problem. I think Dad needs to see the pyschiatrist as I'm worried that his paranoia is going to get worse and worse, he'll end up phoning the police or accusing our neighbour directly. I read about a case similar where a woman started by thinking the new neighbour was whispering about her and ended up claiming the neighbour was breaking into her house, and she ended up in hospital! I'm at my wit's end with this, can anyone offer any advice??