OBJECTIVE

Studies of aging usually focus on trajectories of physical and cognitive function, with far less emphasis on overall mental health, despite its impact on general health and mortality. This study examined linear and nonlinear trends of physical, cognitive, and mental health over the entire adult lifespan.

METHODS

Cross-sectional data were obtained from 1,546 individuals aged 21-100 years, selected using random digit dialing for the Successful AGing Evaluation (SAGE) study, a structured multicohort investigation that included telephone interviews and in-home surveys of community-based adults without dementia. Data were collected from 1/26/2010 to 10/07/2011 targeting participants aged 50-100 years and from 6/25/2012 to 7/15/2013 targeting participants aged 21-100 years with an emphasis on adding younger individuals. Data included self-report measures of physical health, measures of both positive and negative attributes of mental health, and a phone interview-based measure of cognition.

RESULTS

Comparison of age cohorts using polynomial regression suggested a possible accelerated deterioration in physical and cognitive functioning, averaging 1.5 to 2 standard deviations over the adult lifespan. In contrast, there appeared to be a linear improvement of about 1 standard deviation in various attributes of mental health over the same life period.

CONCLUSIONS

These cross-sectional findings suggest the possibility of a linear improvement in mental health beginning in young adulthood rather than a U-shaped curve reported in some prior studies. Lifespan research combining psychosocial and biological markers may improve our understanding of resilience to mental disability in older age and lead to broad-based interventions promoting mental health in all age groups.