Effects of educational attainment on the clinical expression of Alzheimer's disease: results from a research registry.

The "reserve" hypothesis suggests that education should affect the clinical expression of Alzheimer's disease (AD), but results from studies examining this idea are not consistent. In a single study, we evaluated the effects of educational attainment on three aspects of the clinical expression of AD: age at symptom onset, rate of cognitive decline, and survival. Subjects were 258 persons with mild- or moderate-stage Alzheimer's, drawn from our AD Research Registry. With statistical adjustment for confounding variables present in a clinic-based design, we found that higher educational attainment was associated with slightly earlier reports of symptom onset and a slower rate of cognitive decline on the Mini-Mental State Exam (MMSE). Education did not affect time of survival until death. We conclude that, for subjects in our sample, education had modest effects on aspects of the clinical expression of AD. These effects were not fully consistent with predictions derived from the "reserve" hypothesis.