松田 修

The reliability and validity of the Subjective Burden Scale (SBS) were investigated in 255 Japanese family caregivers of elderly relatives with dementia. Values of the Cronbach's alpha reliability, split-half reliability (r), and test-retest reliability (r) were .87, .80, and .72, respectively. The SBS score was significantly positively correlated with the degree of mental health, which was assessed with the Japanese version of the 60-item General Health Questionnaire (r = .41). The family caregivers who gave up the caregiving of their relatives showed significantly higher SBS scores than those who did not. The SBS scores for caregivers indicated satisfactory predictive validity both in the degree of their mental health and in the prospects of family caregiving about 6 months later. These findings suggest that the SBS is adequately reliable and valid and can be used to assess the subjective burden of Japanese caregivers.

To examine early intellectual deficits in elderly patients with dementia of the Alzheimer type (DAT), 25 mildly impaired patients with DAT and 25 normal controls were compared using the Japanese version of the Wechsler Adult Intelligence Scale-Revised (WAIS-R). The two groups did not differ significantly in age, years of education, or sex ratio. Based on Horn's modified fluid and crystallized model, the WAIS-R subtests were classified into two categories (i.e., fluid intelligence and crystallized intelligence). The DAT group showed a significantly lower crystallized intelligence score, whereas the fluid intelligence scores did not differ significantly between the two groups. When the subtests were examined individually, the subtests for crystallized intelligence (i.e., information, comprehension, and similarities) were found to show the most significant deficits. These results suggest that elderly subjects with mild DAT have more impaired crystallized intelligence than those without dementia.