but arent the biological markers of Alzheimer's still theoretical? i thought that is part of why a cure is so hard to come by -- we don't know if it's the plaqu

but arent the biological markers of Alzheimer's still theoretical? i thought that is part of why a cure is so hard to come by -- we don't know if it's the plaques or something else. so if you measure a drug that reduces plaques but you don't measure its affects on cognition how do you know you are making progress?