From adolescence on, human beings continue to grow and mature. Aging can be defined as “the sum of all the changes that normally occur in an organism with the passage of time.”3 Demographers, social scientists, and developmental psychologists consider young adulthood to be roughly between ages of 21 and 40 and middle adulthood to be between the ages of 40 and 65.⁴ Aging, like adulthood itself, is complex and varies from one person to another. The rate at which individuals age is highly variable, but so is the way they adapt to age-related changes and illness. Aging also gives rise to feelings of anxiety in a way no other area of human development does. Failing intellectual or biological functions in the middle years can become a preoccupation for your patient. For example, during this period the pure joy of physical activity experienced in younger years may acquire a sober edge. One of us overheard a man who for years has enjoyed running just for the sport of it tell his friend, “Yeah, my running will probably guarantee that I live 5 years longer, but I will have spent that 5 years running!”

Adults may also worry about the age-related changes that begin to take place in their body structures and functions. Suddenly, forgetfulness is no longer something to be taken lightly but could portend more serious problems generally associated with age. Perhaps the anxiety that aging provokes is due to the close relationship most of us believe exists between biological development and illness, decline, and death.⁵ Rather than view aging in this way, gerontologists have proposed the concept of compressed morbidity, which suggests that people may live longer, healthier lives and have shorter periods of disability at the end of their lives. The focus of health care then becomes one of prevention, health improvement for chronic disease, and postponement of disability or death rather than cure.⁶ In Chapter 17 we will discuss different views of aging and their impact on your interactions with older patients

In human beings the lifespan is thought to be about 110 to 120 years. In Western nations the average life expectancy is said to be 78.7 years, although this varies according to race and other variables (Black females, 78 years; Black males, 71.8 years; White females, 81.3 years; and White males, 76.5).⁷ The 10 leading causes of death for all age groups in the US are listed in Table 16-1.⁷ Cause of death varies according to race and sex, but this table provides a general idea of the types of illnesses you will encounter most often with adult patients. You will note that many of these causes of death are chronic diseases. Chronic disease is a major health problem in the United States. One in four Americans has multiple (two plus) chronic diseases, and the burden of chronic disease among racial and ethnic minorities is notably disproportionate.⁸ Conditions such as diabetes, depression, and cardiovascular disease are now being diagnosed and treated earlier in adulthood than ever before.

As science progresses we learn more about how individual genes, biology, and behaviors interact with the social, cultural, and physical environment to influence health outcomes. Targeting prevention, illness management, and lifestyle modification in young and middle adulthood can increase quality of life and prevent the development and severity of chronic disease in older adulthood. Young adulthood is often referred to as the healthy years and the hidden hazards. Individuals in early and middle adulthood tend to underestimate the impact that poor lifestyle choices may have on their overall health span.

As discussed in Chapter 15, it is during late adolescence that self-identity begins to form. These processes of identity exploration and consolidation continue in the beginning of early adulthood (generally between the ages of 17 and 24). Adulthood is not defined by a single factor, rather an integration of cognitive development, physical development, and societal experience. How individual’s transition through adulthood is heavily influenced by experiences in previous stages of life.

In the span of a few generations, the path to adulthood has changed dramatically. Today’s young people are taking longer to leave home, attain economic independence, marry, and form families than did their peers half a century ago.9 These longer transitions put strains on families and institutions (such as health care systems) that work with young adults. For example, adults who have children might believe that they have moved through an adult developmental task of parenting children, only to find their children returning home after a divorce or unemployment. Therefore, a parent or parents who might have been rejoicing in an empty nest and time for each other may find their adult children under their roof once again and with grandchildren in tow.

Thus, the societal context of delayed acquisition of independence, earlier physical maturation characteristic of modern cultures, pressures on young people to grow up fast, return of adult children to their parents’ home, and delayed childbearing all complicate the traditional views held about progression through adulthood.

Even if we hold several variables constant (e.g., age, gender), it is still difficult to predict how two adult patients would react to the same diagnosis. Consider the example of Ms. McLean and Ms. Jeon, both of whom have just learned that they have in situ cancer of the cervix.

During adulthood, there is another aspect to acting responsibly: it involves having a high regard for the welfare of others. The adult must find a way to support the next generation by redirecting attention from him or herself to others. In other words, the adult learns to care.10 This involves empathy for the predicaments that befall others in life. The acts may flow from a free will, but the will must operate in accordance with reasonable claims and justifiable expectations of other people. The claims of society on a person peak during the middle years, so “acting responsibly” must be interpreted in terms of how completely the person fulfills the conditions of those claims.

For instance, in Hindu culture, one stage of acting out one’s karma involves active engagement in the affairs of family and business. Only when an individual has successfully completed these tasks may he or she move on to higher, more contemplative levels of existence.

One way to view the matter in our culture is to review the discussion of self-respect in Chapters 4 and 5. Although our discussion there was on you, the same principles apply to adult patients. This basic value is among the most essential ingredients of “the good life.” During the adult years, most people perceive their self-respect as being vulnerable to the judgments of others: One’s self-respect at least partially depends on the extent to which he or she commands the respect of employer, family, and friends. This idea is related to our concept of “reputation”: One commands respect by giving due consideration to society’s claims. Hiltner notes, correctly we believe, that, to a large extent, even the personal values of the middle years must include a regard for others. For most, it is a highly social period when interdependencies are complex and pervasive.¹¹

Adulthood sometimes involves people going back to previous developmental tasks such as establishing an identity if they did not resolve these issues previously in late adolescence or early adulthood. For example, in a study of gay males in middle adulthood, the researcher found that “these men were facing issues befitting their chronological age (nongay issues that had been worked on while leading a double life), as well as unresolved identity issues from the past.”¹² The key point of this study is that the subjects were initially working through the earlier stage of development rather than reworking earlier developmental issues that can occur throughout adult development.