Assessment issues in clinical trials of tetrahydroaminoacridine and studies to alter decline in Alzheimer disease.

The concept that Alzheimer disease (AD) and senile dementia of the Alzheimer type (SDAT) are the same disease, the increase in the elderly population, and the knowledge of AD neurochemistry have considerably expanded our knowledge regarding the pathophysiology of this disease. Improvement in clinical evaluation has resulted in diagnostic accuracy approaching 85%. Clinical drug trials currently being carried out are being designed either to improve the core symptoms of the disease or to alter the natural rate of decline. Issues regarding the assessment of patients in clinical trials and the utility of instruments have not yet been completely resolved.