A recent study showed a class of drugs known as anticholinergics block the binding of the neurotransmitter acetycholine.  Wikipedia says, "Alzheimer's disease involves a substantial loss of the elements of the cholinergic system, and it is generally accepted that the symptoms of Alzheimer’s disease are related to this cholonergic deficit, particularly in the cerebral cortex and other areas of the brain."  I TRY to break this down in language that I hope is helpful.  One thing we know - be careful of the medications you take.