In recent years, there has been a growing interest in understanding the effects of neighborhood conditions on psychological wellbeing. This dissertation used the Multi-Ethnic Study of Atherosclerosis (MESA) and the Chicago Community Adult Health Study (CCHAS) to examine (1) cross sectional and prospective associations of neighborhood social cohesion, violence, and aesthetic quality with depressive symptoms in MESA, (2) cross-sectional associations of neighborhood social support (residential stability, family structure, social cohesion, reciprocal exchange, social ties) and stressors (perceived violence, perceived disorder, physical decay, physical disorder, safety, population density) with depressive symptoms in the CCAHS, and (3) cross-sectional associations of the percent of people of the same racial/ethnic background in subjects' neighborhoods and depressive symptoms in MESA. The first study found that lower levels of social cohesion and aesthetic quality and higher levels of violence were cross-sectionally associated with higher mean CES-D scores in both men and women in MESA, while associations of neighborhood characteristics with incident depression were in the expected direction for women only (although not statistically significant). The second study found that greater neighborhood social support was associated with lower levels of depressive symptoms amongst women, while greater neighborhood stressors was associated with higher levels of depressive symptoms in men in the CCAHS. Adjusting simultaneously for stressors, social support, and neighborhood socioeconomic status did not alter associations. Study 3 concluded that living in a neighborhood with a higher percentage of residents of the same racial/ethnic background was associated with increased levels of depressive symptoms amongst African American men and decreased CES-D scores amongst Hispanic men and women and Chinese women. Adjusting for other neighborhood characteristics strengthened associations between depressive symptoms and neighborhood racial/ethnic concentration amongst Hispanics, but did not explain the association in African American men. These three studies all illustrate the role that neighborhood environments play in both increasing and decreasing depressive symptoms in residents. Policies and programs that work towards enhancing neighborhood social support and lessening neighborhood stressors, in addition to typical individual-based treatments and therapies, may help address the important public health problem of depression and depressive symptoms.