This article (freely available and published online in advance of press) may be a fairly technical and difficult article to follow for the lay reader, but snippets provide some insights into its findings and implications. The authors have looked at data which showed higher prevalence of non-affective psychoses (as opposed to bipolar-type psychoses) in some parts of London and:
“…sought to investigate whether the incidence of psychotic disorders varied between neighborhoods in East London, after adjustment for individual-level age, sex, ethnicity, and social class. We tested whether such variation was associated with several neighborhood-level environmental factors, including absolute (deprivation, social fragmentation, social cohesion, and population density) and relative (inequality, ethnic density, and ethnic separation) measures.”
We identified marked spatial variation in the relative risk of nonaffective psychotic disorder in East London, not explained by individual-level factors including age, sex, ethnicity, and social class. Together with our observation that the incidence of affective psychoses showed no such spatial variation, our data replicate previous studies to have found such differences with respect to the environment.3–5 Our study extends these findings, however, by using appropriate spatial multilevel models to demonstrate that the incidence of nonaffective psychosis was independently associated with increased deprivation, income inequality, and population density. When we studied the influence of socioenvironmental factors in specific ethnic groups, we observed that ethnic separation and ethnic density were associated with nonaffective psychosis risk for people of black Caribbean and black African, respectively.
The authors make several conclusions make from the results, two of which are:
“…living in more deprived neighborhoods may expose people to a range of stressful experiences, resultant from lower social and economic investment, including higher rates of crime and antisocial behavior, poorer educational, leisure and health facilities, and more physical health problems, all of which may induce stress with further consequences for mental health.57 Individuals who lack sufficient social or financial capital to offset exposure to these stressful events, either by drawing upon social support or by moving to less-deprived neighborhoods,55 may face chronic exposure to such threats over the life course; several studies have observed an association between lower social support and psychosis risk.”
“Our findings suggest that inequality, absolute deprivation, and the experience of living in dense, urban environments in adulthood may contribute to psychosis risk. Continued efforts to integrate social neuroscience with social epidemiology should help reveal how and when environmental exposures over the life course have critical effects on brain processes that increase psychosis risk.”