Longitudinal studies of neighbourhood social cohesion and mental health: a systematic review with meta-analysis

OBJECTIVES: This review aimed to examine how neighbourhood social cohesion has been defined and operationalized in longitudinal mental health research, and determine its associations with depression, anxiety, suicidality, psychological distress, and positive mental health across the lifecourse. METHODS: Relevant articles were identified on February 6, 2024, in Medline, Embase, PsycINFO, CINAHL, and Web of Science. Eligible studies used quantitative longitudinal designs. Risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale for Cohort Studies (NOS). Included articles were synthesized using direction of effect narrative synthesis and random-effects meta-analysis. Reporting was guided by the PRISMA-2020 statement. RESULTS: Narrative synthesis included 42 articles representing 30 independent study samples, with the majority of articles on depression (n = 26). Out of a maximum score of nine, the median NOS score was seven (interquartile range = 2, range = 5, 9); higher scores indicate lower risk of bias. Overall, based on direction of effect, 28 articles reported positive associations between neighbourhood social cohesion and better mental health outcomes (17 were statistically significant). Meta-analysis of 12 depression articles found that higher neighbourhood social cohesion was associated with lower depression scores (n = 62,677, β = -0.054, 95%CI = -0.091, -0.018). CONCLUSION: Higher neighbourhood social cohesion is longitudinally associated with lower risk of depression; evidence for other mental health outcomes remains limited. While multi-item scales have been widely used to capture the multidimensional nature of neighbourhood social cohesion, no single definition of neighbourhood or method of measuring neighbourhood social cohesion was consistently used. Efforts towards establishing a consensus would enhance comparability.