Middle Adulthood and Aging
Health, as described by Hahn and Payne (1998), is the blend of physical, emotional, social, intellectual, spiritual, and occupational resources that help one master the developmental tasks necessary for a satisfying and productive life. Each phase of life presents unique challenges that evolve over time. Even though people are living longer, perceptions of aging may evolve more slowly. Life expectancy continues to expand as a result of advances in medical technology; this has redefined the stage of life known as midlife. At the beginning of the twenty-first century, people forty to sixty years old are considered to be in midlife. Less than a century ago, they were considered to be in old age.
Psychiatry and Behavioral Science: An Introduction and Study Guide for Medical Students
Mach, Burton and Baron, D., "Middle Adulthood and Aging" (2009). PCOM Scholarly Papers. 1472.