This is the final version. Available on open access from BMC via the DOI in this recordAvailability of data and materials: The data that support the findings of this study are available on request from the corresponding author [SBC]. The data are not publicly available due to them containing information that could compromise research participant privacy/consent.Background Relationships in various forms are an important source of meaning in people’s lives that can benefit their health, wellbeing and happiness. Relationship distress is associated with public health problems such as alcohol misuse, obesity, poor mental health, and child poverty, whilst safe, stable, and nurturing relationships are potential protective factors. Despite incre...