SEASON OF BIRTH AND ALZHEIMERS-DISEASE - A POPULATION-BASED STUDY IN SAGUENAY-LAC-ST-JEAN QUEBEC (IMAGE PROJECT)

The birth distribution of 399 cases of Alzheimer's disease (AD) identi fied in the region of Saguenay-Lac-St-Jean (Quebec) was compared with that of: (a) the population currently living in the area; and (b) the population born during the same period in the area. AD cases have been recruited since 1986 by the IMAGE Project. Cases and controls were gr ouped according to the month of birth and according to the day of birt h using density estimation. Analyses showed a significant deficit of b irths in the month of May. We believe these preliminary results deserv e further attention and we suggest two possible explanations that coul d lead to a deficit of AD births at specific periods during the year.