Introduction

Older adulthood is a developmental stage at the end of the lifespan when an individual experiences a number of significant changes in life circumstances. These age-associated events include changes in physical appearance and body composition, which can result in increased vulnerability to both acute and chronic physical illness as well as functional limitations such as decreased mobility and diminished sensory capacities. In addition, older people generally experience numerous losses and stressors, such as moving to a fixed income, increasing expenses, and loss of retirement investments; death of family members, friends and loss of social network; alterations in social position; changes in housing and work; and spousal caregiving and widowhood. The ability to adapt positively to these types of stressful life event and to other adversities is likely an important factor in “successful” aging.

Currently, older adults are among the fastest growing subgroups of the population in the USA as in many other countries. Recent estimates suggest that there are approximately 37 million people aged 65 years and over in the USA, accounting for over 12% of the total population (US Federal Interagency Forum on Aging-Related Statistics, 2008). By the year 2030, the number of individuals age 65 years and over is expected to nearly double to 71.5 million, accounting for approximately 20% of the US population (US Federal Interagency Forum on Aging-Related Statistics, 2008).