My husband experienced dementia related psychosis episodes recently where he was uncontrollable. Quite scary to say the least. Advice from our neurologist was to start him on a low dose Seroquel, a sedative medication which has significantly helped the psychosis episodes. Sundowning continues to be troublesome but manageable. That being said, this medication was what he needed at this stage of his illness. I hope you find the best medication to treat this unforgiving illness for your husband.