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 services-led and are likely to require multidisciplinary and multi-agency approaches.