Abstract

Objectives
Loneliness and low social support are associated with poor mental health in the perinatal period (pregnancy and one year postnatal). However, no reviews have explored systematically whether interventions aimed at improving perinatal mental health also improve loneliness and/or social support satisfaction (SSS). We aimed to address this gap in the literature, to improve our understanding of mechanisms underlying interventions addressing perinatal mental health and loneliness and/or SSS.

Methods
We conducted a systematic review of studies evaluating the effectiveness of interventions to address perinatal mental health and also measuring either loneliness or SSS. We searched six electronic databases and eight grey literature sources. Two reviewers independently screened papers for eligibility and assessed risk of bias. Findings were presented as a narrative synthesis.

Results
Of 6,422 unique retrieved records, we included 26 eligible studies (measuring both mental health and either loneliness or SSS). Of these, four studies measured mental health and loneliness, 21 measured mental health and SSS, and one measured mental health and both loneliness and SSS. Only eight of the 26 included studies were deemed to present low risk of bias. Of 17 included randomised controlled trials (RCTs), six identified significant improvements in loneliness/SSS compared to controls, but only three of these also identified significant improvements in anxiety and/or depression. Interventions with some evidence of effectiveness in improving loneliness/SSS were those facilitated by professionals, whilst those with some evidence of effectiveness in improving mental health were those that involved peer contact. Only one study conducted formal mediation analysis to delineate the pathways between these outcomes, finding no support for their hypothesis that an improvement in SSS mediates a reduction in depression.

Conclusion
We found evidence that some (but not all) interventions that address perinatal mental health also improve loneliness and/or SSS. We found little empirical work to explain the pathways between these variables. Our findings suggest the need for further work exploring the relationships between loneliness/SSS and mental ill-health among perinatal parents. This will identify opportunities to prevent the onset or worsening of mental ill-health in parents (and their children) at risk of mental health problems.