The Psycho-Immunological Shift Theory (Pist)

Background. Psychoneuroimmunology has documented associations between psychological stress, adverse experience in childhood and the onset or course of autoimmune and chronic inflammatory disease. The part played by the expression or suppression of emotion, as a distinct and measurable variable, remains poorly defined and is seldom tested directly. Aim. This thesis presents the Psycho-Immunological Shift Theory (PIST) as a testable theoretical framework. It proposes that sustained, unresolved and poorly expressed emotional load acts, in susceptible people, as a contributory factor that modifies the probability and course of immune dysregulation, through a chain of five links: exposure, neuroendocrine and autonomic activation, a shift towards a low-grade inflammatory profile, disruption of barriers and microbiome, and loss of tolerance. Approach. The work is a theoretical and integrative synthesis. It draws together the literature of immunology, neuroendocrinology, the neuroscience and psychology of emotion, developmental science and the sociology of health. It states a conceptual expression (PAM) that balances risk and protective factors; sets out six axioms, ten propositions and six hypotheses; describes four mechanistic pillars (the neuroendocrine axes, the inflammatory cascade, neurochemistry with microglia, and the triangle of endothelium, blood-brain barrier and microbiome); proposes a theoretical biomarker panel; reviews the application of the framework to specific immune-mediated diseases; examines carefully, and with limits, what it might mean for care; and designs a staged research programme with criteria for refutation stated in advance. It contains no primary data, and all numerical values that appeared in earlier versions of the theory are treated as conceptual illustrations only. Main points. Throughout, the thesis separates established knowledge from the hypotheses of the theory and from illustration. It examines competing explanations, namely shared genetic vulnerability, reverse causation, primarily inflammatory models, and purely biological accounts. It treats the risk of blaming patients as a central ethical problem. It argues that the most informative tests are those in which the PIST and a general stress model predict differently, and that a distinct construct, temporal order, mediation,