The effect of education on dementia occurrence in an Italian population with middle to high socioeconomic status.

OBJECTIVE: To explore the relation between education and dementia prevalence by computing the odds ratios (ORs) for different educational levels after adjustment for age, gender, occupational level, and life habits.
METHODS: A two-phase community study including 495 elderly subjects with middle to high socioeconomic status, aged more than 60 years and with a high percentage of noneducated subjects, was carried out in the province of Ravenna, Italy. Dementia and dementia type were clinically diagnosed using DSM-III-R diagnostic criteria.
RESULTS: A higher prevalence of dementia was observed among noneducated subjects of both genders. Comparing no education with any education, the OR (adjusted for age, gender, and occupation) was 4.7 (95% CI = 2.3 to 9.6). The association, although present in all age groups, was extraordinarily strong among the youngest subjects (61 to 69 years) (OR = 139.5, 95% CI = 6.4 to 3,024.6) and decreased with increasing age. Life habits, such as smoking and alcohol consumption as well as current or previous history of hypertension, did not change the results. There was no significant difference in dementia prevalence among less well-educated (up to 3 years of education) and better-educated subjects (more than 3 years of schooling) after age and gender were taken into account. Similar findings were found for Alzheimer's disease and vascular dementia separately.
CONCLUSIONS: Having no education is associated with dementia independent of gender, occupation, life habits, and hypertension. This association was stronger among younger old persons, and decreased with increasing age. The findings suggest that the first decade of life is a critical period for developing dementia later in life. The decrease in dementia risk may be due to schooling, according to the cerebral reserve hypothesis, or to other factors associated with a higher educational level during childhood.