If AD is a real disease with no cure, why would they even respond to placebo over the short-term?
Obviously there is more at play. Some patients respond to just being treated (taking a pill or getting a shot or getting an IV infusion), whether there is sugar in the vehicle or actual drug.
Patients are excluded from trials for many reasons.
Just look at clinicaltrials.gov...every trial has inclusion and exclusion criteria.
And, I wasn't saying exclude EVERYONE that improves, I would just exclude those who are super responders to placebo (greater than a certain threshold).
If a patient is shown to respond remarkably to placebo, seems like as good a reason as any to exclude that patient in a neuro trial.