PhD defence: Space Meets Time: A Life-Course Perspective on the Associations Between Neighborhood Environments and Mental Health Problems during Adolescence and Young Adulthood

Mental health problems often begin early in life, with around three-quarters of all lifetime mental disorders starting before the age of 24. Where young people live may play an important role in their mental health. However, we still know relatively little about how neighborhood environments change as young people grow up, whether experiences in earlier neighborhoods continue to matter later in life, and whether different environmental conditions (e.g., air pollution, socioeconomic disadvantage) affect mental health in different ways. Guided by the Life Course of Place framework, this dissertation examined how a range of physical and social neighborhood characteristics are related to mental health from adolescence into young adulthood. The findings show that young people’s environmental exposures are not fixed. They change over time, depending on the type of environmental condition, whether young people move, and their stage of development. The findings also suggest that mental health may be related not only to the neighborhood where a young person currently lives, but also to environments experienced earlier in life. Individual and family circumstances are important in understanding these long-term relationships because they may influence both where families live and young people’s mental health. Overall, this dissertation suggests that improving current neighborhood conditions may benefit young people’s mental health, and additional support may also be needed for those who have previously experienced adverse environments.