Towards unravelling and addressing the dynamics of depression in high-risk urban populations through a complexity lens

There is an urgent need to better understand the emergence and management of depression in urban contexts, particularly among the most vulnerable groups. This is underscored by (I) the high global prevalence of depression and (II) the ongoing urbanisation worldwide. Although cities are attractive in many respects, epidemiological studies suggest that depression is more common in cities. Depression likely develops through the interplay of multiple factors over time, ranging from the individual to the urban and even societal level. This thesis utilizes a complexity science approach and aims to (I) gain more insight into some of the factors and their dynamical interactions that are relevant for depression in vulnerable urban groups, and (II) to understand if – and how – interventions (i.e., ‘perturbations’) can influence these dynamics to contribute to the prevention and treatment of depression. In Part One, we present a conceptual framework that aims to guide future urban mental health research from a complexity science perspective, including the subsequent research in this thesis. Part Two uses difference complexity science methods to examine how dynamics between factors at the intersection of ethnic discrimination and socioeconomic position contribute to the risk of depressive disorder in ethnic minority groups. In Part Three, we examine the impact of perturbations on dynamics underlying risk of depression at different levels: affect dynamics in recurrent depression at the individual level, and mental resilience from a dynamical systems perspective at the population level. The thesis concludes with discussion implications for future urban mental health research and policy.