Observations and suggestions on antidementia drug development.

Recent advances in the theoretical neurosciences have suggested a number of novel strategies that might be applied to prevent and/or retard the progression of Alzheimer disease. Whether or not these interventions will succeed cannot be determined on theoretical grounds, however; the value of each new stratagem must be evaluated in patients with Alzheimer disease. How best to conduct clinical studies of disease-modifying treatments remains a controversial subject. The author reviews and compares two clinical trial designs that may prove useful in assessing whether or not a putative treatment actually modifies the course of dementia.