Determinants of carer stress in Alzheimer's disease.

OBJECTIVES: To explore the impact of subgroups and individual symptoms of non-cognitive disturbance on the carers of Alzheimer's disease patients.

DESIGN: Cross-sectional study using clinically valid scales to assess patient symptomatology and self-report questionnaires to measure carer variables.

SETTING: Old age psychiatry outreach services in South and Central Manchester.

SUBJECTS: 100 patients with Alzheimer's disease living at home and their carers.

MAIN OUTCOME MEASURES: Subjective burden and distress in carers.

RESULTS: Separate statistical analyses were performed for subgroups and individual symptoms of non-cognitive disturbance. For subgroups, multivariate analyses identified depression and behavioural disturbances in patients as significant predictors of subjective burden in carers. Carer distress was predicted by depression, psychosis and cognitive impairments in patients and carer gender. For individual symptoms of non-cognitive disturbance, three features of depression in patients (mood-related signs, physical signs and behaviour changes), walking disruptions and the patient-carer relationship predicted of subjective burden in carers. Variance in the level of carer distress was accounted for by sleep disruptions, hallucinations and mood-related depressive features in patients and carer gender.

CONCLUSION: The findings confirm that the non-cognitive features of Alzheimer's disease are stressful for carers and indicate specific relationships between mood-related and behavioural signs of depression, walking and sleep disruptions and hallucinations in patients and adverse carer outcomes. Patient depression and the mood-related signs of depression in particular were the most consistent and powerful predictors of psychological morbidity in carers. Intervention strategies need to identify and target troublesome behaviours in patients and aim to either change these behaviours or alter the way carers respond to them. Thus, interventions need to be symptoms-rather than service-led and are likely to require multidisciplinary and multi-agency approaches.