Introduction: Symptoms of dementia bring about challenges to couples' relationships. Relationship-focused support has been highlighted to be of significant importance for sustained relationship quality and to reduce the negative impact of dementia on the dyadic relationship. This review aimed to explore the 'what' and 'why' of interventions aimed at couples where one partner has a diagnosis of dementia and in which the couple jointly participate.

Method: Searches were performed in Academic Search Premier, CINAHL, PsycINFO, PubMed, Scopus and Web of Science from January 2000 to August 2017.

Results: Six studies were included. Objectives for the person with dementia was related to cognitive function and for the care partner the objectives were related to well-being. The majority of the outcomes were mirrored by the objectives and focused on cognitive function for people with dementia and depression and relationship quality for care partners. Our findings indicate that people with dementia should be included in the assessment of the relationship in order to gain an overall picture of relationship dynamics and to increase tailored support in couple-centred interventions.

Conclusions: The findings of this review indicate that joint interventions for people with dementia and care partners are lacking a genuine dyadic approach where both partners' views of their relationship are valued. In order to identify targets for support and to use the appropriate outcome measures, the quality of the relationship should be recognised and taken into account. Moreover, there is a lack of a salutogenic approach in couple-centred interventions in which couples' strengths and resources can be identified and supported.