Can Late Life Social or Leisure Activities Delay the Onset of Dementia?

ne of the questions asked most often by older individu0 als is whether there are activities they might engage in to prevent or postpone the onset of dementia. This question is of consequence not only to older individuals but to society. The prevalence of dementia rises exponentially, doubling with every 5 years of chronological age between ages 65 and 85.’ A 5-year delay in onset of symptoms would halve the number of dementia patients. In the United States, where the economic costs of caring for demented older persons are over 100 billion dollars per year, the discovery of activities that delay the onset of dementia would likely have the same consequences as the discovery that diet and exercise delay the onset of cardiovascular disease has had on improving the health of older individuals and extending life span. In an article in this issue of the Journal of American Geriatrics Society, Fabrigoule et al.’ report that traveling, odd jobs or knitting, and gardening are associated with a lower risk of developing dementia in a cohort of 2040 randomly selected home-dwelling residents of Gironde, France, aged 65 and older, who were nondemented at their baseline screening and who were then followed for at least 3 years. This study highlights two significant methodological issues inherent in identifying late life risk or protective factors for dementia. The first issue is dissociating protective or risk factors from the effects of early prediagnosis symptomatology. A major problem in determining whether successful engagement in an activity delays the onset of cognitive impairment or whether the lack of successful engagement is an early symptom was well stated by Hultsch et al.,3 who investigated the association of cognitively demanding activities and cognitive performance. These investigators stated that “given the present data set . . . we are unable to demonstrate whether activity styles act to maintain cognitive performance or whether healthy cognitively able individuals choose, or are more able to participate, in an active life style.. . ” Hultsch et al. suggested that only through a longitudinal study could this be determined. Fabrigoule et al.’ have carried out a longitudinal study to circumvent this difficulty. Yet the problem persists. Dementia was diagnosed in their cohort using DSM-111-R criteria. DSM-I11 and DSM-111-R criteria have been adopted worldwide because they are highly accurate; when a subject is diagnosed as demented using these criteria, there is more than a 95% likelihood that the diagnosis is But this accuracy is obtained by the conservative nature of these criteria, which require the presence of both functional and cognitive impairment, with cognitive impairment involving