Older people with mental health needs and dementia often face difficulties with daily living and community participation, requiring the intervention of social care services. However, cognitive and emotional needs often mean that mainstream support is not appropriate. In England, mental health support workers may attempt to address these concerns, to prevent mounting care needs and the potential for institutional care. Yet, their work has not been researched to identify good practices and to understand the mechanisms through which they engage older people. A new qualitative study used semi-structured interviews and focus groups with specialist support workers (n= 22), managers (n= 7), homecare staff (n= 4) and service users and carers (n= 6). The latter group were interviewed by co-authors with lived experiences of dementia and care. Participants were recruited from mental health services, home care organisations and third-sector agencies across the North of England in 2020-2021. The study identified three themes that described support worker activities. First, 'building trusting relationships' identified steps to establish the foundations of later interventions. Paradoxically, these may involve misleading clients if this was necessary to overcome initial reluctance, such as by feigning a previous meeting. Second, 're-framing care' referred to how the provision of care was positioned within a narrative that made support easier to engage with. Care framed as reciprocal, as led by clients, and having a positive, non-threatening description would more likely be accepted. Third, 'building supportive networks' described how older people were enabled to draw upon other community resources and services. This required careful staging of support, joint visits alongside workers in other services, and recognition of social stigma. The study was limited by constrained samples and covid context requiring online data collection. The study recommends that support workers have more opportunity for sharing good practice across team boundaries, and improved access to specialist training.