Dear Sue, There is a tendency to assume PD is the reason for every condition or symptom that occurs. While it is quite possible that the condition is Alzheimer's-type dementia, or that Aricept might help your father, it is also quite possible that your father could be suffering from B vitamin Deficiency. Unless his physician has already done so, your father should be checked for this. Some physicians will give B12 shots, note whether any improvements occur, and if so, will continue the shots. Older adults produce less of the stomach acid needed to metabolize B12, therefore the vitamin slowly depletes. Deficiency resembles Alzheimer's dementia, and eventually becomes irreversible. I always check my clients' food diaries for B vitamin intake (among other things) and frequently recommend a B complex. I urge you to question your physician closely about this. Neurologists in particular are well aware of the need for B vitamins. Best regards, Kathrynne > his Doctor about it. He's definately not with it most of the time > mentally...seems a lot like Alzheimer's to me. His last Dr. visit Mom was > basically told nothing else could be done, he's had PD for 18 years.