Relationships between dispositional optimism and cognitive functions in community-dwelling middle aged and older persons

Abstract

Background: Positive psychology is recognized as an important contributing factor in terms of well-being. Positive psychological constructs as dispositional optimism or purpose in life have been linked to positive health outcomes. However, there is little research in relation to it within the dementia field. In the present study we investigate an association between dispositional optimism and cognitive functions in the middle aged and the older. Methods: Participants were 555 community-dwelling middle aged and older persons without dementia. The cognitive functions were measured by means of logical memory test, Money road test, Stroop test, D-CAT (digit cancellation test), verbal fluency test and MMSE. Dispositional optimism were assessed using 10 item questionnaire adapted from Japanese versions of the Life Orientation Test-Revised. Results: Participants were divided into three dispositional optimism groups (upper, middle and lower) based on the score of the questionnaire. ANCOVA, using age, sex and education as covariate, dispositional optimism group as independent variables, and scores on the cognitive tasks as dependent variables, was conducted to investigate the effect of positive psychological constructs on the age-related decline of cognitive functions. A significant main effect of dispositional optimism was shown for the score on digit cancellation test, Stroop test and MMSE. The score of these cognitive functions in lower optimism group was lower than that in the other groups. Conclusions: Greater dispositional optimism is associated with higher cognitive functions. It became clear that positive psychological constructs could reduce a risk of cognitive decline in old persons.