Longitudinal association between neighbourhood-level social capital and incidence of major psychiatric disorders: a cohort study of 1.4m people in Stockholm County, Sweden
Year: 2025
Type: preprint
Study design: Observational Study
Abstract: Background: Greater neighbourhood-level social capital is cross-sectionally associated with lower incidence of non-affective psychotic disorders, but longitudinal evidence is missing, and specificity to this outcome or across population groups is unclear. We investigated these issues in a large, population-based cohort in Stockholm County, Sweden, linked to prospectively-collected ratings of neighbourhood-level social capital.Methods: All Swedish-born people living in Stockholm County between 2002-2016, aged 14-64 years, were followed from cohort entry until first diagnosis of ICD-10 severe mental illness (non-affective psychotic disorder, affective psychotic disorder or bipolar disorder without psychosis), out-migration from Stockholm County, 65th birthday, death, or 31 December 2016, whichever was sooner. We derived three neighbourhood-level social capital exposures (political trust, welfare trust, personal trust) for 813 neighbourhoods, averaged from individual scores from 23,510 independent, randomly-selected respondents to the 2002 Stockholm County Public Health survey; most respondents were Swedish-born to two Swedish-born parents (72.2%). We used multilevel proportional hazards models of each outcome-exposure association, adjusted for extensive confounder sets informed by directed acyclic graphs. We tested a priori interactions between social capital exposures and parental region-of-origin, and inspected the sensitivity of our models to various scenarios, including endogeneity of our social capital measures. Results: Our cohort included 1,467,128 participants, of whom 17,760 (1·2%) received a first diagnosis of severe mental illness during follow-up. Greater neighbourhood-level personal trust was associated with reduced incidence of non-affective psychotic disorder, but only amongst those of Swedish (adjusted hazard ratio [aHR] associated with a one standard deviation increase in trust: 0·91; 95%CI: 0·84-0·98) or European (aHR: 0·80; 95%CI: 0·69-0·92) heritage (interaction p-value: <0·0001). Conversely, greater neighbourhood-level personal trust increased these rates for those of North African and Middle-Eastern (aHR: 1·46; 95%CI: 1·08-1·96) or Sub-Saharan African (aHR: 1.76; 1.00-3.08; p=0·049) heritage. We observed similar effect modification for bipolar disorder without psychosis (p<0·0001), but not affective psychotic disorders (p<0·79). Political and welfare trust showed few associations with any outcome. Results were robust to sensitivity analyses, including two instrumental variable approaches. Interpretation: Social capital had longitudinal effects on several mental health outcomes, but could be protective or harmful depending parental region-of-origin, a potential indicator of outgroup position.
Institutions: University College London, Karolinska Institutet, Region Stockholm
Language: English
Subfield: Health
Field: Social Sciences
Domain: Social Sciences
Open Access status: green
Awards: G158726132, G210416921, Psychiatric care among migrants, descendants of migrants, and Swedish born,–what are the differences, and why does it differ?, Psychosis risk over the life course: A multilevel, longitudinal investigation of social, economic and physical environmental risk factors at different stages in life.
OpenAlex ID: W4410550731