Zammit Stanley, Lewis Glyn, Rasbash Jon, Dalman Christina, Gustafsson Jan-Eric, Allebeck Peter
MRC Centre for Neuropsychiatric Genetics and Genomics, Department of Psychological Medicine and Neurology, Cardiff University, Wales, UK.
Arch Gen Psychiatry. 2010 Sep;67(9):914-22. doi: 10.1001/archgenpsychiatry.2010.101.
Incidence of schizophrenia and other nonaffective psychoses is greater in urban than rural areas, but the reason is unclear. Few studies have examined whether both individual and neighborhood characteristics can explain this association. Furthermore, as has been shown for ethnicity, the effect of individual characteristics may depend on neighborhood context.
To examine (1) whether individual, school, or area characteristics are associated with psychosis and can explain the association with urbanicity and (2) whether effects of individual characteristics on risk of psychosis vary according to school context (reflecting both peer group and neighborhood effects).
Multilevel longitudinal study of all individuals born in Sweden in 1972 and 1977. Diagnoses were identified through linkage with the Swedish National Patient Register until December 31, 2003.
Population-based.
A total of 203 829 individuals with data at individual, school, municipality, and county levels.
Any nonaffective psychosis, including schizophrenia (881 subjects; 0.43% cumulative incidence). For the study of interactions, the outcome was any psychosis (1944 subjects; 0.95% cumulative incidence).
Almost all the variance in risk of nonaffective psychosis was explained by individual-level rather than higher-level variation. An association between urbanicity and nonaffective psychosis was explained by higher-level characteristics, primarily school-level social fragmentation. We observed cross-level interactions between individual- and school-level markers of ethnicity, social fragmentation, and deprivation on risk of developing any psychotic disorder, all with qualitative patterns of interaction.
The association between urbanicity and psychosis appears to be a reflection of increased social fragmentation present within cities. The qualitative interactions observed are consistent with a hypothesis that certain characteristics that define individuals as being different from most other people in their local environment may increase risk of psychosis. These findings have potentially important implications for understanding the etiology of psychotic disorders and for informing social policy.
精神分裂症和其他非情感性精神病的发病率在城市高于农村，但原因尚不清楚。很少有研究探讨个体特征和社区特征是否都能解释这种关联。此外，正如种族方面所显示的那样，个体特征的影响可能取决于社区环境。
研究（1）个体、学校或地区特征是否与精神病相关，并能否解释与城市化的关联；（2）个体特征对精神病风险的影响是否因学校环境而异（反映同伴群体和社区影响）。
对1972年和1977年在瑞典出生的所有个体进行多层次纵向研究。通过与瑞典国家患者登记处的关联确定诊断，截至2003年12月31日。
基于人群。
共有203829名个体，拥有个体、学校、市和县层面的数据。
任何非情感性精神病，包括精神分裂症（881名受试者；累积发病率0.43%）。对于相互作用的研究，结局为任何精神病（1944名受试者；累积发病率0.95%）。
非情感性精神病风险的几乎所有变异都由个体层面而非更高层面的变异解释。城市化与非情感性精神病之间的关联由更高层面的特征解释，主要是学校层面的社会碎片化。我们观察到个体层面和学校层面的种族、社会碎片化和贫困指标之间在发生任何精神障碍风险上存在跨层面相互作用，所有这些相互作用都具有定性模式。
城市化与精神病之间的关联似乎反映了城市中社会碎片化的增加。观察到的定性相互作用与这样一种假设一致，即某些使个体在其当地环境中与大多数其他人不同的特征可能会增加患精神病的风险。这些发现对理解精神障碍的病因以及为社会政策提供信息可能具有重要意义。
