Objectives: Depression is a common condition in dementia and has a substantial impact on quality of life and wellbeing. There is limited evidence on how depressive symptoms in the person with dementia impact on the carer, and vice versa. The aim of this study is to investigate dyadic relationships between depressive symptoms and capability to live well in both people with dementia and their carers and to examine whether people with dementia who do not have a carer are more vulnerable to the impact of depressive symptoms than those who have a carer.
Methods: Using a large cohort study of 1547 community-dwelling people with mild to moderate dementia and 1283 carers in Great Britain, a Bayesian analysis framework was developed to incorporate dyads (N = 981), people with dementia whose carers did not participate (N = 127), people with dementia who did not have a carer (N = 137), and dyads with missing data (N = 302) and estimate actor and partner relationships between depressive symptoms and capability to live well, which was expressed as a latent factor derived from measures of quality of life, life satisfaction and wellbeing.
Results: Depressive symptoms in people with dementia and carers had negative associations with capability to live well both for the individual and for the partner. Compared to those who had a carer, depressive symptoms had a greater impact on capability to live well in people with dementia who did not had a carer.
Conclusions: The impact of depression may extend beyond the person experiencing the symptoms. Future interventions for depressive symptoms should utilise this potential wider impact to understand and optimise treatment effects.
Keywords: Dementia; depression; dyadic analysis; epidemiology; quality of life/wellbeing.