The development of Alzheimer's disease (AD) later in life may be reflective of environmental factors operating over the course of a lifetime. Educational and occupational attainments have been found to be protective against the development of the disease but participation in activities has received little attention. In a casecontrol study, we collected questionnaire data about 26 nonoccupational activities from ages 20 to 60. Participants included 193 people with probable or possible AD and 358 healthy controlgroup members. Activity patterns for intellectual, passive, and physical activities were classified by using an adaptation of a published scale in terms of ''diversity'' (total number of activities), ''intensity'' (hours per month), and ''percentage intensity'' (percentage of total activity hours devoted to each activity category). The control group was more active during midlife than the case group was for all three activity categories, even after controlling for age, gender, income adequacy, and education. The odds ratio for AD in those performing less than the mean value of activities was 3.85 (95% confidence interval: 2.65-5.58, P < 0.001). The increase in time devoted to intellectual activities from early adulthood (20 -39) to middle adulthood (40 -60) was associated with a significant decrease in the probability of membership in the case group. We conclude that diversity of activities and intensity of intellectual activities were reduced in patients with AD as compared with the control group. These findings may be because inactivity is a risk factor for the disease or because inactivity is a reflection of very early subclinical effects of the disease, or both.case-control study ͉ dementia ͉ epidemiology ͉ leisure ͉ recreation

Previous studies have established cross-cultural methods to screen for ageing-related dementia and susceptibility genes, in particular Alzheimer's disease (AD) among the Canadian Cree, African Americans and Yoruba in Nigeria. We determined whether the Community Screening Interview for Dementia (CSID), translated into Kikuyu, a major language of Kenya, could be used to evaluate dementia of the Alzheimer type. Using two sets of coefficients of cognitive and informant scores, two discriminant function (DF) scores were calculated for each of 100 elderly (>65 years) Nyeri Kenyans. When the cut-off points were selected for 100% sensitivities, the specificities of the DF scores were remarkably similar (93.75%) in the Kenyan sample. We propose the adapted CSID can be utilised to detect dementia among East Africans. We also show that apolipoprotein E ε4 allele frequencies were high (∼30%) and not different between normal subjects and those with probable AD. There was no evidence to suggest years of education or vascular factors were associated with dementia status.

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.