Two linked studies assess the feasibility of involving care staff in reducing the prevalence of depression in homes for older people. Mental health training was provided for care staff, delivered by members of a Community Mental Health Team for the Elderly. The research programme used quantitative and qualitative methods to evaluate the effects of a theoretical training for care staff, a system of mentoring care staff to reinforce the training; and a care-planning intervention for the management of depression which combined psychosocial and medical approaches. The training programme was positively evaluated by the recipients, the trainers and the researcher who observed it. The ability of care staff to detect depression improved significantly over time, and depression was reduced to below case-level in seven of the eight depressed residents who participated in the care-planning intervention. This research suggests that psychosocial interventions that involve collaboration between carers and residents, supported by a Community Mental Health Team, may have an important part to play in supplementing medical management of depression in residential care homes.