PhD defence: Longitudinal Associations between Physical Activity, Neighborhood Environments, and Adult Mental Health

Mental health is an important part of well-being, yet depression and anxiety are becoming more common in the Netherlands. This thesis examines how mental health is shaped not only by individual behaviour, especially physical activity, but also by changes in the physical and social environments of the neighbourhood. 

Using Dutch longitudinal panel data and a systematic review of earlier studies, this thesis explores how physical activity, neighbourhood conditions, and residential relocation relate to mental health over time. The findings show that increases in physical activity are associated with better mental health, and that self-esteem partly explains this relationship, especially for moderate-to-vigorous activity. The review also shows that neighbourhood socioeconomic disadvantage and higher urbanicity are linked to poorer mental health, while evidence for other neighbourhood factors is less consistent. 

The empirical analyses further show that worsening neighbourhood air pollution is associated with poorer mental health, whereas greater exposure to blue space is linked to better mental health. These effects are not the same for everyone: women appear more affected by increasing air pollution, and lower-income groups are more vulnerable to neighbourhood deprivation. The thesis also finds that moving to neighbourhoods with lower air pollution, lower population density, and lower socioeconomic deprivation is associated with improved mental health after relocation. 

Overall, this thesis shows that mental health is influenced not only by where people live, but also by how their environments and behaviours change over time. The findings offer insights for urban planning, public health, and policies aimed at creating healthier living environments.