マルチリンガルと認知症—ブラジルと台湾の研究から

Multilingualism and Dementia: From the Studies in Brazil and Taiwan

われわれのブラジル・台湾の研究より，認知症有病率は多言語使用・環境・文化に左右されないが，認知症の言語劣化は言語使用頻度・環境と関係し，両言語とも劣化するが非対称であることが示された。また多言語使用による認知予備力と認知症保護効果が示された一方で，多言語使用者の言語機能衰退は認知症の精神症状，妄想や抑うつ状態と関係し，安心できる言語環境の提供が精神症状を軽減させたことが示された。言語機能評価を認知症ケアに生かす必要が示唆された。

Abstract

Our studies in Brazil and Taiwan revealed that the prevalence of dementia was independent of environment, culture, and use of multilingualism. However, language deterioration in dementia was found to be related to its frequency of use and the environment, and both language, and deterioration were asymmetric. Although the cognitive reserve and protective effect of multilingualism on dementia were shown, the decline in language function was found to be related to psychiatric symptoms of dementia, delusions, and depression which were relieved by providing a reliable language environment. It was suggested that language function evaluation should be considered for dementia care.