Alzheimer disease (AD) is a medically and financially overwhelming condition, and incidence rates are expected to triple by 2050.Despite decades of research in animal models of AD, the disease remains incompletely understood, with few treatment options. This review summarizes historical and current AD research efforts, with emphasis on the disparity between preclinical animal studies and the reality of human disease and how this has impacted clinical trials. Ultimately, we provide a mechanism for shifting the focus of AD research away from animal models to focus primarily on human biology as a means to improve the applicability of research findings to human disease. Implementation of these alternatives may hasten development of improved strategies to prevent, detect, ameliorate, and possibly cure this devastating disease.