Aging and cognition.

A substantial portion of elderly people experience declines in mental capacities. While these changes are often attributable to serious dementing illnesses such as Alzheimer's disease, a surprising number result from apparently normal aging processes. The effects of senescence on cognition may be indirect (i.e., gait instability leading to falling and subsequent head trauma); however, they may have a more direct and subtle impact on the brain. The evidence available to date suggests that only a limited range of cognitive domains are susceptible to these aging effects. Perhaps the most important are short-term memory functions. The specific character of these and other age-related cognitive deficits are reviewed.

Dementing illnesses in rural populations: the need for research and challenges confronting investigators.

Expansion of the world's elderly populations has increased concerns about aging-related medical disorders like Alzheimer's disease and other dementias. In the United States, one fourth of those older than age 65 and at greatest risk for developing dementia live in rural environments that may influence its manifestation. The objectives of this study were to determine the need for and potential benefits of further epidemiological research concerning dementia and similar disorders in rural U.S. populations and to identify pertinent methodological issues related to rural dementia research. This study employed a National Library of Medicine (MEDLINE) document search based on the key words "cognitive disorders," "dementia," "Alzheimer's disease," and "rural," followed by recovery of literature resources references in the bibliographies of selected articles. Nineteen studies focusing on dementia or related disorders in rural settings have been reported from around the world. While four of these were conducted in the United States, only one rural dementia prevalence study has been undertaken in this country. Because of methodological variability, comparisons of prevalence estimates between these rural studies, as well as with those from urban investigations, is difficult. Nonetheless, there is reason to believe that certain potentially dementing illnesses are more common in rural populations. There is also evidence to suggest that the screening instruments commonly used in such studies tend to misclassify rural elders as "false positive" dementia cases. Information regarding dementing disorders, particularly Alzheimer's disease, in rural populations is scarce. Preliminary observations that dementia may be more common in rural settings and that rural families are more likely to maintain their dementing elders in the community imply that further rural dementia research could yield important insights into the risk factors for these illnesses, the variables influencing their course, and the methods by which they can be more effectively managed. A determination of the reliability and validity of commonly used dementia screening instruments in rural populations would represent an important advancement in this area of research.

The clinical epidemiology of Alzheimer's disease.

Alzheimer's disease is a more common and malignant illness than was appreciated just 2 decades ago. In addition to being a major cause of mortality, it is costly and uniquely distressing for patients and their families. All indications are that the problem will grow as elderly populations expand. Fatalism regarding AD is premature, however. Much has been learned about this disease in only a few years, and it is hoped that this rate of discovery can be maintained or even accelerated in the future.

Suicide in the United States, 1951-1988: constant age-period-cohort rates in 40- to 44-year-old men.

Age-specific suicide rates in the United States between 1951 and 1988 were shown in cohort, cross-sectional, and age group formats. Despite considerable variation among women and younger and older men, suicide rates among 40- to 44-year-old men have remained stable. Since suicide is strongly influenced by psychosocial stressors, the constant suicide rates in middle-aged men suggest a consistency in the stress experienced by this population subgroup.

The establishment of clinical cutoffs in measuring caregiver burden in dementia.

Although several scales have been developed to assess burden, their clinical utility has been limited by the absence of relevant cutoff points. Clinical data from 140 primary caregivers seeking a dementia evaluation for a family member were analyzed to establish the psychometric properties of a caregiver burden screen. Results indicate that the cutoff values were both sensitive and specific to negative caregiving outcomes. These findings suggest that use of a burden screen may assist clinicians when assessing the adequacy of caregiving arrangements in dementia.

Clinical assessment of family caregivers in dementia.

Development of an integrated family assessment inventory based on the Double ABCX and Circumplex models of family functioning and its clinical utility was evaluated with 121 primary family caregivers from a cognitive disorders program. The proposed model predicted a significant proportion of the variance associated with caregiver stress and strain. Several aspects of the caregiving arrangement also emerged as key features in predicting caregiver depression. These findings supported the model's central premise that both dyadic (caregiver-patient) and systemic (caregiver-family) variables are salient in assessing the impact of family caregiving with dementia.

Alzheimer's disease as a diagnosis of exclusion.

Although dementia is frequent among the elderly, and usually the result of Alzheimer's disease, other illnesses may be responsible. A diagnostic approach to discover such treatable disorders is detailed in this paper.