[Self- and informant-rating mood scales applied in elderly persons with Alzheimer's dementia, with or without a language disorder].

INTRODUCTION: Alzheimer's Dementia (AD) may be associated with symptoms of depression. In AD, problems of language expression or understanding will arise sooner or later. The aim of this study was to determine whether elderly persons with AD, with or without a language disorder, experience difficulties understanding and answering mood related questions. In addition to this, it was our object to test the validity of the answers of nurses as informants, on the mood of an elderly client.

METHODS: 53 elderly persons, living in care homes, and their nurses, took part in the study. 25 participants had been diagnosed with Alzheimer's disease, 28 participants had no cognitive impairment. Language skills were tested using the SAN-test (Stichting Afasie Nederland) and subtests of the Aachen Aphasia Test (AAT). Mood was assessed with the Beck Depression Inventory-second edition (BDI-II-NL) and the Geriatric Depression Scale (GDS-30).

RESULTS: There were no significant differences in scores on the mood related questionnaires between participants without cognitive impairment and participants with Alzheimer's disease, with or without a language disorder. The correlation between self- and informant-rating was very limited. In general, nurses reported more depressive symptoms than the elderly persons did themselves. Disparities between self- and informant-ratings varied from informant scores overestimating low self-ratings of depression to informant scores underestimating high self-ratings.

CONCLUSION: Alzheimer's disease, whether or not it is complicated by a language disorder, does not disturb the normal score distribution on either test (BDI or GDS). This means that elderly persons with Alzheimer's disease are capable of adequately answering questions related to their own mood. However, considerable discrepancies were found between observer- and self-ratings of emotional wellbeing. Therefore it is important to not only take into account the information of an informant when testing for depression, but also the elderly person's own assessment of their mood.