Social support is a well-recognised protective factor for children’s mental health. Whilst many interventions exist that seek to mobilise social support to improve children’s mental health, not much is known about how to best do this. We sought to generate knowledge about the ways in which social support can be mobilised to improve children’s mental health. We conducted a systematic review, which followed the principles of a realist synthesis. The following databases were searched: PubMed, CINAHL, Ovid MEDLINE, PsychINFO, EMBASE, Child and Adolescent Studies, EconLit and SocINDEX. Studies were included if the age of participants was between 0 and 18 years and they evaluated or described programme theories of interventions that sought to improve children’s mental health by mobilising social support. Relevance and quality of studies were assessed, and data were extracted and analysed narratively. Thirty-three articles were included. Studies varied substantially with regard to the detail in which they described the processes of mobilising social support and expected mechanisms to improve children’s mental health. Those that provided this detail showed the following: Intervention components included explaining the benefits of social support and relationships to families and modelling friendly relationships to improve social skills. Pathways to improved outcomes reflected bi-directional and dynamic relationships between social support and mental health, and complex and long-term processes of establishing relationship qualities such as trust and reciprocity. Parents’ ability to mobilise social support for themselves and on behalf of children was assumed to impact on their children’s mental health, and (future) ability to mobilise social support. Although interventions were considered affordable, some required substantial human and financial resources from existing systems. Mobilising social support for vulnerable children can be a complex process that requires careful planning, and theory-informed evaluations can have an important role in increasing knowledge about how to best address social support and loneliness in children.

Stigma can have devastating health and wellbeing impacts, not just on people with mental health problems, but on people associated with the stigmatized person. This is called stigma-by-association. Children whose parents have mental health problems are a particularly vulnerable group, and stigma acts as a mechanism, contributing to the transgenerational transmission of mental disorders. The current study is a systematic mixed studies review, synthesizing knowledge about how this group of children experience stigma-by-association. Overall, 32 studies were included, after a systematic search including quantitative, qualitatative, and mixed methods studies. The methodological quality was assessed and qualitative content analysis undertaken. We grouped children's stigma experiences into four dimensions, i.e., experienced stigma, anticipated stigma, internalized stigma, and structural discrimination. Results show that stigma is an important factor in those children's lives, and needs further investigation in qualitative and quantitative research. The current study emphasizes the importance of anti-stigma interventions and campaigns.