Neighborhood ethnic density and suicide risk among different migrant groups in the four big cities in the Netherlands

Recent studies suggested a favorable association between the ethnic density of the neighborhood and the risk of psychotic disorders among ethnic minorities. In this study, it was investigated whether this so-called ‘ethnic density hypothesis’ is also relevant to suicide risk, which is not sensitive to bias associated with ethnic differences in access to health care and reflects a broad range of mental health problems.

Suicides in the four big cities in the Netherlands during 2000–2011 were ascertained using the cause of death register of Statistics Netherlands and analyzed in a multilevel Poisson model in relation to individual- and neighborhood-level characteristics.

With increasing non-Western minority density, the adjusted rate ratio (RR) of suicide in non-Western immigrants compared to native Dutch persons decreased from 0.69 to 0.39 (P < 0.001). This was explained by higher suicide rates among Dutch persons (RR = 1.28, P = 0.048) and lower rates among non-Western persons (RR = 0.72, P = 0.004) in neighborhoods with high (>55.9 %) compared to neighborhoods with low non-Western minority density (<36.5 %). Similar results were found for Turkish, Moroccan, Surinamese/Antillean and other non-Western subgroups separately. Compared to personally matched controls, non-Western cases (i.e., those who committed suicide) more often moved house to own-group high-dense areas and less often to own-group low-dense areas in the 5 years prior to suicide.

Our findings support the beneficial influence of the presence of the own ethnic group in the neighborhood on suicide risk among non-Western minorities. As moving to minority more dense areas prior to suicide was observed, this influence of ethnic density as measured on population level may have been underestimated.