A comprehensive systematic review and multilevel meta-analysis of the ethnic density effect in psychosis

Abstract

<p>BackgroundA group density effect in psychosis has been observed, whereby minority groups living in areas where there is a high proportion of their own group are at a lower risk of psychosis than minorities residing in neighbourhoods where their group is less represented. However, there is conflicting evidence over whether the group density effect differs by minority group, and limited investigation into other potential moderators.AimsTo conduct a comprehensive systematic review and meta-analysis of the group density effect in psychosis, examine moderating factors, and discuss possible mechanisms driving the effect.MethodFour electronic databases were systematically searched for studies reporting on the group density effect in psychosis. Evidence was qualitatively synthesised, and a three-level ‘multilevel’ meta-analysis was conducted on eligible studies. We assessed whether the pooled effect was moderated by broadly and specifically defined minority groups. Country, time, geographic unit, and outcome were also tested as moderators. We drew upon a wider evidence-base to explore potential mechanisms.ResultsThe search yielded 2652 unique articles, twenty-eight studies were included in the qualitative synthesis, and fourteen of these were eligible for meta-analysis. A ten percentage-point decrease in own-group density was associated with a 36% increase in psychosis risk [OR=1.36 (95% CI 1.11-1.65), p=0.003]. In line with the qualitative synthesis, the pooled effect was moderated by broadly defined minority groups [F6, 74=3.58, p=0.004] and when more specific minority groups were considered, a stronger moderating effect was observed [F21, 59=4.93, p&amp;lt;0.0001]. Other moderator tests were non-significant.ConclusionsThis is the first review to provide meta-analytic evidence that the risk of psychosis posed by lower own-group density environments is not uniform across minority groups. This may reflect experiences of disempowerment which may arise differently in particular groups. This is explored further, along with implications of findings and avenues for future research.</p>

Not belonging where others do: a cross-sectional analysis of multi-level social capital interactions on health and mental well-being in Wales

“…Another important question is whether people's outsider status depends on explicit social identities and communities, or a more implicit sense of belonging. Research into the group density effect, the positive correlation between people's mental health and the proportion of the local population their social group represents [38][39][40], shows that socially salient group identities, such as ethnicity, can lead to group density dynamics, but it is unclear on whether they rely on explicit identities. Research on newly formed Brexit identities in the United Kingdom, where group density effects for 'remainer' and 'leaver' identities only manifested after the referendum on European Union membership, suggests that such explicit identities, rather than broader underlying cultural mismatch, may be a necessary component of such effects.…”