We examined the association between complexity of the main lifetime occupation and changes in cognitive ability in later life. Data on complexity of work with data, people, and things and on four cognitive factors (verbal, spatial, memory, and speed) were available from 462 individuals in the longitudinal Swedish Adoption/Twin Study of Aging. Mean age at the first measurement wave was 64.3 (s.d. = 7.2) and 65% of the sample had at least 3 waves of data. Occupational complexity with people and data were both correlated with cognitive performance. Individuals with more complex work demonstrated higher mean performance on the verbal, spatial, and speed factors. Latent growth curve analyses indicated that, after correcting for education, only complexity with people was associated with differences in cognitive performance and rate of cognitive change. Continued engagement as a result of occupational complexity with people helped to facilitate verbal function before retirement, while a previous high level of complexity of work with people was associated with faster decline after retirement on the spatial factor. KeywordsOccupational complexity; cognitive change; retirement As the prevalence of cognitive impairment continues to rise in parallel with increasing life expectancy, preserving cognitive health has become a growing concern among older adults. Associated with this concern has been an effort to identify factors that may help maintain cognitive function into older adulthood.Despite the fact that most people spend a substantial portion of their lives at work, our understanding of the relationship between occupational activity and cognition is limited. Schooler and colleagues' concept of "environmental complexity" provides some clues (Schooler, 1984;Schooler, Mulatu, & Oates, 2004). They posit that exposure to complex environments at work or during leisure enables continued practice of cognitive skills and Correspondence to: Deborah Finkel, Ph.D., Indiana University Southeast, 4201 Grant Line Road, New Albany, IN 47150, Phone: 812-941-2210, Fax: 812-941-2170.edu. Publisher's Disclaimer: The following manuscript is the final accepted manuscript. It has not been subjected to the final copyediting, fact-checking, and proofreading required for formal publication. It is not the definitive, publisher-authenticated version. The American Psychological Association and its Council of Editors disclaim any responsibility or liabilities for errors or omissions of this manuscript version, any version derived from this manuscript by NIH, or other third parties. The published version is available at www.apa.org/journals/pag. NIH Public Access Author ManuscriptPsychol Aging. Author manuscript; available in PMC 2010 September 1. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript hence facilitates cognitive functioning. Several studies have supported the environmental complexity hypothesis with respect to work environment and cognitive function. Using data from the Maastricht Aging Study based in th...

We examined the association between risk of dementia or Alzheimer's disease (AD) and occupation by using measures of complexity of work with data, people, and things. The study included 10,079 members of the population-based Swedish Twin Registry who were participants in the HARMONY study. We diagnosed dementia by means of a two-stage procedure--cognitive impairment screening followed by full clinical evaluation. We analyzed data with case-control and cotwin control designs. The cotwin control design provides control over genetic and familial factors. In the case-control study, controlling for age, gender, and level of education, we found that more complex work with people was associated with reduced risk of AD. Greater complexity of work with people and data was protective in twin pairs discordant for AD. Findings suggest that greater complexity of work, and particularly complex work with people, may reduce the risk of AD.

Exercise at midlife may reduce the odds of dementia in older adulthood, suggesting that exercise interventions should be explored as a potential strategy for delaying disease onset.

This study examined whether participation in leisure activities during early and middle adulthood was associated with reduced risk of Alzheimer's disease. The sample consisted of 107 same-sex twin pairs discordant for dementia and for whom information on leisure activities was self-reported more than 20 years prior to clinical evaluation. A factor analysis of these activities yielded three activity factors: intellectual-cultural, self-improvement, and domestic activity. Matched-pair analyses compared activities within the discordant twin pairs while controlling for level of education. For the total sample, participation in a greater overall number of leisure activities was associated with lower risk of both Alzheimer's disease and dementia in general. Greater participation in intellectual-cultural activities was associated with lower risk of Alzheimer's disease for women, although not for men.

Dementia plays a central role in risk of NHP. Understanding risk factors for NHP in this relatively vulnerable population has important policy implications.