April 16, 1999

Geriatric psychiatrists will face a larger and more diverse aging population in the next century. By the year 2050, about 20 percent of Americans will be over the age of 65 and about 5 percent will be over age 85, according to geriatric psychiatrist Soo Borson, M.D., who spoke last month at the annual meeting of the American Association of Directors of Psychiatric Residency Training (AADPRT) in Santa Monica, Calif.

Adults aged 65 and older make up about 12 percent of the current population, noted Borson, director of geropsychiatry services in the department of psychiatry and behavioral sciences at the University of Washington Medical Center, Seattle. She is also president of the American Association for Geriatric Psychiatry.

As the size of the elderly population increases, prevalence rates of mental disorders are expected to rise over the next 30 to 40 years, said Borson. Mental disorders, excluding dementia, are expected to increase by 275 percent by the year 2030 for adults over 65 and by 67 percent in adults under 65, she said.

To meet the need for psychiatric care for the aging population in the United States, workforce projections made by the National Institute on Aging about a decade ago estimate that about 5,000 to 7,000 clinical geropsychiatrists will be required soon after the turn of the century. Currently, there are just over 2,300 board-certified geriatric psychiatrists in the United States, said Borson.

A minimum of 500 additional geriatric psychiatrists will be needed as full-time academicians to equip a cadre of psychiatrists to manage the diverse mental disorders in older adults and respond to this population's unique treatment needs. Academicians also will be needed to guide the development of new research and treatments, said Borson.

She referred to the 1991 book Psychiatric Disorders in America: The Epidemiologic Catchment Area (ECA) Study that found that 13 percent of adults aged 65 and up had mental disorders other than dementia. "However, there are compelling reasons to think that these rates are lower than the actual proportion of older adults with clinically significant symptoms who need psychiatric treatment."

Based on data from other epidemiological studies and clinical observations of special features of psychiatric disorders in older adults, 15 percent to 25 percent of this age group have been found to have significant symptoms of affective disorders; 17 percent to 20 percent had clinically significant anxiety; and 7 percent to 8 percent abused alcohol or were alcohol dependent, according to Borson. Rates of schizophrenia, estimated at 0.2 percent of older Americans, may also have been underestimated in the ECA studies, she said.

Moreover, because "many mental illnesses manifest differently in older adults, milder impairments may have been missed." For example, anxiety in the elderly is frequently associated with depression, but there is no diagnostic category for anxious depression in DSM-IV, as there is in the International Classification of Diseases (ICD)-9, said Borson.

The prevalence of neurodegenerative diseases, which are common in older adults, especially Alzheimer's and Parkinson's disease, will certainly rise as the population ages. Mortality from these disorders is projected to increase in the total population by as much as 231 percent by 2040, noted Borson.

Ethnic minorities, however, whose elderly populations have an even greater growth rate, are expected to have the highest increases in mortality from neurodegenerative diseases. "Published data suggest that their prevalence will increase 373 percent in ethnic minority elderly, as compared with 166 percent in white, older adults," noted Borson.

Dementias are currently estimated to affect about 37 percent to 50 percent of adults aged 85 and up and about 8 percent to 20 percent of adults aged 65 to 85, she added.

Borson noted that most older patients with psychiatric disorders are cared for by primary care physicians, and only a small minority of patients visit community mental health centers. "Geriatric psychiatrists have an important role to play in educating primary care physicians. We also have much to learn from the other disciplines involved in the care of the elderly including psychologists, nurses, and social workers."

To learn more about geriatric psychiatry and national initiatives to improve geriatric care, visit these organizations' Web sites: American Association for Geriatric Psychiatry www.aagpgpa.org; National Institute on Aging www.nia.gov; Administration on Aging www.aoa.dhhs.gov; and the Alzheimer's Association www.alz.org. -C.L.