Neighborhood Characteristics at Birth and Positive and Negative Psychotic Symptoms in Adolescence: Findings From the ALSPAC Birth Cohort.

Francesca Solmi,Glyn Lewis,Stanley Zammit,James B Kirkbride

doi:10.1093/schbul/sbz049

Abstract

BackgroundUrban birth is associated with risk of non-affective psychoses, but the association with subclinical positive and negative symptoms is less clear, despite emerging evidence. Further the extent to which these findings are confounded by polygenic risk scores (PRS) for schizophrenia is also unknown.MethodsUsing data from the Avon Longitudinal Study of Parents and Children, linked to census geographical indicators, we examined whether various indices of urbanicity at birth were associated with negative and positive psychotic symptoms at age 16 and 18 years, respectively. We used logistic regression models, controlling for child’s ethnicity, maternal age, education, marital status, social class, depressive symptoms, other neighborhood exposures, and, in a subsample of children of white ethnicity (N = 10 283), PRS for schizophrenia.ResultsAmongst 11 879 adolescents, those born in the most densely populated tertile had greater odds of reporting positive psychotic experiences, after multivariable adjustment (odds ratio [OR]: 1.57, 95% confidence intervals (CIs): 1.14–2.17). Adolescents born in the most socially fragmented neighborhoods had greater odds of negative symptoms, after multivariable adjustment (OR: 1.43, 95% CI: 1.06–1.85). Although we found that greater schizophrenia PRS were associated with an increased risk of being born in more deprived and fragmented (bot not more densely populated areas), these associations were not confounded by PRS.InterpretationBirth into more densely populated and socially fragmented environments increased risk of positive and negative psychotic phenomena in adolescence, respectively, suggesting that different forms of neighborhood social adversity may impinge on different psychopathophysiologies associated with the clinical expression of psychosis.

Highlights

Psychotic disorders may lie at one end of an “extended psychosis phenotype,”[1,2] which includes transient symptoms and subthreshold psychotic experiences that may, for some, be a precursor for later clinical diagnoses
Schizophrenia is more common among individuals born in more densely populated and deprived areas,[15,16,17,18] exhibiting a dose–response relationship,[16] and some, not all,[19] emerging evidence suggests that subthreshold psychotic experiences follow similar patterns with respect to urban birth[9,10,11] and residence.[12,13,14]
Most studies of subclinical symptoms have focused on positive psychotic phenomena, with only 2 studies having investigated the effect of urban living on negative symptoms, finding equivocal results.[20,21]

Summary

Introduction

Psychotic disorders may lie at one end of an “extended psychosis phenotype,”[1,2] which includes transient symptoms and subthreshold psychotic experiences that may, for some, be a precursor for later clinical diagnoses. Schizophrenia is more common among individuals born in more densely populated and deprived areas,[15,16,17,18] exhibiting a dose–response relationship,[16] and some, not all,[19] emerging evidence suggests that subthreshold psychotic experiences follow similar patterns with respect to urban birth[9,10,11] and residence.[12,13,14] no study to date has investigated whether specific aspects of the social environment at birth (ie deprivation, social fragmentation, population density) are related to subclinical psychotic symptoms. Most studies of subclinical symptoms have focused on positive psychotic phenomena, with only 2 studies having investigated the effect of urban living on negative symptoms, finding equivocal results.[20,21] Studying whether the urbanicity– psychosis association is general in nature, or specific to certain symptoms could provide important insights on causal mechanisms underlying etiology.[20]

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Conclusion