Differential effects of ethnic density on the risk of postnatal depression and personality dysfunction

The relationship between ethnic density and psychiatric disorder in postnatal women in the UK is unclear. To examine the effect of own and overall ethnic density on postnatal depression (PND) and personality dysfunction. Multilevel analysis of ethnically mixed community-level data gathered from a sample of 2262 mothers screened at 6 weeks postpartum for PND and personality dysfunction. Living in areas of higher own ethnic density was protective against screening positive for PND in White women (z = -3.18, P = 0.001), even after adjusting for area level deprivation, maternal age, relationship status, screening positive for personality dysfunction, parity and geographical clustering (odds ratio (OR) 0.98 (95% CI 0.96-0.99); P = 0.002), whereas the effect on personality dysfunction (z = -2.42, P = 0.016) was no longer present once the effect of PND was taken into account (OR = 0.99 (95% CI 0.90-1.0); P = 0.13). No overall ethnic density effect was found for women screening positive for PND or personality dysfunction. In White women, living in areas of higher own ethnic density was protective against developing PND.