Hello, I just discovered this site and have spent the last few hours reading previous discussions. Already I feel a sense of support. In the last 8 months my father, who turned 90 a few weeks ago, has exhibited real signs of paranoia, sudden outbursts of rage and hatred towards others, even old friends and certainly me, and even anti-Semitic rants -- which is shocking and absurd b/c I am part Jewish on my mother's side. Of course, I think these behaviors are signs of dementia, but the problem is that my father is still cognitively sharp. Every doctor who has tested his cognition says he has a mind like a steel trap in terms of memory, vocabulary, reasoning tests, etc. Has anyone else had an elderly parent like this? Frankly, I would feel a little better and a little more understanding if he were diagnosed with Alzheimer's or some other type of dementia.