Yan, HuaThis thesis examines the relationship between neighborhood disadvantage, sense of community, and adolescent drug use. Prior research has found that sense of community has positive effects on adolescent behavior. However, little study has examined the specific impact of sense of community on adolescent drug use. Based on social disorganization theory and the extended social disorganization models, this thesis attempts to fill this gap in the literature by testing the hypothesis that sense of community mediates the effects of neighborhood disadvantage on adolescent drug use. Using data from Add Health, correlations and regressions are applied to test the hypothesis. The results partially support the hypotheses. Sense of community is found to mediate the effects of one aspect of neighborhood disadvantage - residential instability, on adolescent drug use.ThesisSocial researchCriminology