Prevalent mental health disorders in the aging population: issues of comorbidity and functional disability. (Mental Health Disorders in Aging).

Older adults are as vulnerable as younger persons to the most prevalent mental health disorders in our population--depression, anxiety, and alcohol abuse. However, less is known about them than about acquired cognitive disorders such as dementia and delirium, which are more troublesome for elders than for younger adults. It is estimated that up to 11% of persons over age 65 and 36% of persons over age 85 have some form of dementia (Rojiani & Morgan, 2000). Gottlieb (2000) projects increases in the numbers of elders with dementia of the Alzheimer's type to as many as 14 million by the year 2040.

Estimates of the other prevalent mental health disorders among persons over age 65 are few and variable. Historically, epidemiologic studies of mental health disorders in both general and clinical populations have used age 54 as a cut off point. Some of the earliest seminal studies about mental health needs of elders included Regier et al. (1988) and Cohen (1991). In the former, the Epidemiologic Catchment Area Program (ECA), which provided the largest population-based data on mental health disorders in the United States, mood and anxiety disorders in elders were estimated at 2.5% and 5.5%, respectively. But in 1991, Cohen suggested that 15% to 25% of elders demonstrated significant symptomotology. In 1992, the National Institute of Health (NIH) concluded that depressive disorders especially are (a) widespread among older adults, (b) frequently comorbid with medical illness, and (c) a serious public health concern. The National Center of Health Statistics (1993) echoed NIH's concern and reported that elderly white males have the highest suicide rates of all age groups. The American Psychiatric Association (1994) contended that, except for dementias, the frequency of most mental health disorders does not increase in the elderly population. However, Kessler, Berglund, and Zhao (1996) estimated that 25% of older people experience specific mental disorders such as depression, anxiety, and substance abuse that are not part of normal aging. Although more current and precise prevalence estimates about mood and anxiety disorders among elders are not available, partly because only 24 of the 50 states and the District of Columbia have operational mental health plans that address screening, crisis intervention, and treatment needs or services for their aging populations (U.S. Department of Health and Human Services, 2000), the Surgeon General (1998,1999) has emphasized the need for health professionals to become more engaged in meeting the mental health needs of elders.

In younger individuals, mental health disorders may occur singly. In elders, however, mental health disorders are frequently comorbid, occurring in conjunction with any one of a number of common chronic illnesses such as respiratory problems, arthritis, diabetes, cardiac disease, and the like. In combination, these disorders impact physical functioning, independence, perceived well-being, quality of life, and health outcomes in subtle and complex ways (Lichtenberg, 1998). The biological and psychological declines that typically accompany aging--stamina and endurance, memory, and alterations in metabolism, to name a few--can be compensated for in some individuals to the extent that their daily functioning is not compromised. But for elders with comorbid mental health and physical impairments, typical declines become more pronounced, threatening their abilities and capacities for self-care.

The relationships between mental health disorders and functional disability in elders may seem obvious; but as Williamson, Shaffer, and Parmelee (2000) note, empirical data suggest the links are complex. Fried and Guralnik (1997) and Fried, Ettinger, Lindh, Newman, and Gardin (1994) posit a spiral over time. A mental health disorder, such as depression or anxiety, increases the risk of both self-perceived and behavioral disability which, in turn, increase the risk of more depression or anxiety. A process of reciprocal reinforcement continues, resulting in greater vulnerability of the individual to further disease and decline in overall health and quality of life. This is a particularly salient issue among persons with disabilities because depression and anxiety are seen in them more frequently than those without disabilities (Centers for Disease Control, 1998). This spiral relationship evolves over time and is exemplified by the following: A co-existing cognitive disorder such as vascular or Alzheimer's dementia attendant to diabetes may erode a person's ability to understand how to take blood glucose measurements and what to do about resultant readings, eroding self-management of the diabetes.

Investigations of comorbidities for factors such as physical functioning, psychological functioning, and psychosocial variables, are relatively recent and few. But, as noted earlier, developing greater understanding of these associations and relationships is of critical concern to better understanding and treatment of a growing aging population in the United States. At the present time, the disciplines concerned with comorbid disorders and the subtle and complex relationships between comorbid mental health disorders, chronic illnesses and disabilities, and functional health outcomes include geriatric neuropsychiatry, behavioral neurology, clinical geropsychology, neuropsychopharmacology, sociology, and related disciplines. Coffey and Cummings (1994), Anderson and Haley (1997), and Haley et al. (1998) note that there is a gross lack of availability of individuals with expertise in gerontologic patient care, education, and research.

General medical and primary care settings are the initial points of health care contact for many elders, including those with mental health disorders. In the past, health care professionals in these settings paid less attention to mental state than the physical. Today, however, nurse practitioners, family physicians, and …