Vanishing Boundaries: A Unifying Account of Multidimensional Emotion Dynamics and Alterations in Depression

Abstract

Emotions are fundamentally integral to shaping both the order and disorders in human lives. Yet, establishing a mathematical framework to describe emotional dynamics and their alteration in mental disorders has proved challenging, leading to a spectrum of partially contrasting theories. Our study seeks to overcomethese challenges by employing dynamic systems theory, the mathematical study of complex systems, their behavior over time, and their responses to externalstimuli. We apply this approach to a dataset containing over 400,000 texts from more than 1,600 individuals, with half reporting a diagnosis of Major Depressive Disorder (MDD), collected from X (previously Twitter). We examined the emotional experiences and significant life events described in these texts acrossa one-month period, that we extracted using state-of-the-art natural language processing. Our analysis then aimed to gain a deeper understanding of how emotions evolve, how they interact, and how, if at all, they are altered by depression. The key result of our research is the discovery of emotion-specific dynamics – the unique ways in which different emotions maintain their influence over time. In individuals diagnosed with MDD, we observed a ’blunting’ of the inter-emotional dynamics; this is not merely a dulling of emotions, but rather a vanishing of the boundaries between them. Our findings thus challenge and unify traditional views in this area: when viewed in isolation, this blending of emotions could be misinterpreted as both augmented emotion and blunted emotions but also as Emotional Context Insensitivity (ECI). Our study therefore offers a principlesmathematical understanding of emotion dynamics and their alterations within mental disorders, potentially leading to more effective therapeutic interventions.