Will drugs help patients with Alzheimer's disease?

Recent studies have shown a defect in the cholinergic system of the cerebral cortex of patients suffering from nonvascular senile dementia. This observation suggests the possibility of instituting some kind of replacement therapy and trial have been carried out. At this juncture it seem pertinent to ask what lessons can we learn from Parkinson's disease, what is the evidence for a biochemical defect, is this defect relevant and can it be remedied? These questions are considered in turn and suggestions are made about the likely difficulties to be overcome in a search for a treatment of dementia.