When does neighbourhood matter? Multilevel relationships between neighbourhood social fragmentation and mental health

Studies investigating relationships between mental health and residential areas suggest that certain characteristics of neighbourhood environments matter. After developing a conceptual model of neighbourhood social fragmentation and health we examine this relationship (using the New Zealand Index of Neighbourhood Social Fragmentation (NeighFrag)) with self-reported mental health (using SF-36). We used the nationally representative 2002/3 New Zealand Health Survey dataset of urban adults, employing multilevel methods. Results suggest that increasing neighbourhood-level social fragmentation is associated with poorer mental health, when simultaneously accounting for individual-level confounding factors and neighbourhood-level deprivation. The association was modified by sex (stronger association seen for women) and labour force status (unemployed women more sensitive to NeighFrag than those employed or not in labour force). There was limited evidence of any association of fragmentation with non-mental health outcomes, suggesting specificity for mental health. Social fragmentation as a property of neighbourhoods appears to have a specific association with mental health among women, and particularly unemployed women, in our study.