The proposed study has four aims: (1) to advance understanding of the relationship between neighborhood structural characteristics and psychological and behavioral health (internalizing and externalizing problems) among urban adolescents and, critically, to investigate key neighborhood-level social process indicators that may influence adolescent well-being;(2) to investigate potential indirect pathways between neighborhood social processes and adolescents'psychological and behavioral health via proximate developmental contexts (i.e., parent and peer relationships) and traumatic experiences (i.e., exposure to community violence);(3) to determine whether neighborhood processes condition the influence of proximate developmental contexts and experiences on adolescents'psychological and behavioral health;and (4) to examine the interdependent contributions of neighborhood context and key demographic characteristics (gender and race/ethnicity) to adolescent health. The project will focus largely on the influence of four specific indicators of neighborhood level processes: (1) collective efficacy, which refers to attachment and mutual trust among residents (i.e., social cohesion) and to the resultant willingness to protect against threats to residents'collective well-being (i.e., informal social controls Sampson, 2003;Sampson, Raudenbush, &Earls, 1997;Sampson &Wilson, 1995);(2) disorder, which refers both to public acts of deviance (e.g., common street crimes such as drug dealing and prostitution, public arguments, public intoxication) and to physical evidence of deviance and decay (e.g., needles/syringes on the streets, garbage on the streets;Skogan, 1990;Sampson &Raudenbush, 1999);(3) social ecologies, which are characterized by the prevalence of conventional outdoor foot traffic and the resulting social control of public spaces (Duany, Plater-Zyberk, &Speck 2000);and (4) institutional resources, which refer to resources such as neighborhood organizations and health care facilities (Leventhal &Brooks- Gunn, 2000). To address study aims, we will use data from the Project on Human Development in Chicago Neighborhoods (PHDCN) - an innovative multi-study project specifically designed to promote understanding of contextual influences on youth development. Analyses will involve three PHDCN data sources: (1) the Longitudinal Cohort Study data from youth in four age cohorts (9, 12, 15, and 18 year olds in 1995) selected from 80 Chicago neighborhoods (N = 2,978);(2) an independent Community Survey of Chicago residents (N=8782;1995);and (3) a Systematic Social Observation study of over 15,000 block faces within the sampled 80 neighborhoods. Our analytic approach will combine multilevel and spatial statistical models to explore key hypotheses. Findings from the study have the potential to illuminate critical pathways through which neighborhood level disadvantage influences adolescent psychological and behavioral health. PUBLIC HEALTH RELEVANCE: The proposed research will contribute to a better understanding of how neighborhood factors affect adolescent psychological and behavioral health. Findings from the research may help guide interventions that aim to address urban adolescent health, both with respect to the types of neighborhoods that should be targeted for intervention and the neighborhood level structural and social process characteristics that are most likely to influence adolescent outcomes.