Mechanistic Reconstruction of Integrative Psychopathology: A Theoretical Framework, Computational Modeling of the Bioenergetic Stability Index (ISB), and Mendelian Randomization Causal Analysis

The contemporary psychiatric landscape is undergoing an epistemological transition from fragmented nosological models toward an integrated systems biology approach. This paper proposes a comprehensive theoretical framework and a simulation-based computational model that reconstructs anxiety disorders and major depressive disorder (MDD) as emergent manifestations of systemic bioenergetic failure. The framework postulates that peripheral somatic irritation, particularly Gastroesophageal Reflux Disease (GERD), acts as a persistent allostatic load generator that ultimately depletes brain mitochondrial energy capacity. This concept is consistent with the Allostatic Triage Model of Psychopathology (ATP Model). By synthesizing population genetics data through bidirectional Mendelian Randomization (MR) causal analysis, this study provides preliminary evidence for a systemic pathophysiological pathway linking gastrointestinal dysfunction to central nervous system emotional architecture. To quantify this phenomenon, the manuscript formulates the Bioenergetic Stability Index (ISB), a mathematical algorithm integrating heterogeneous biomarkers, including peripheral inflammation, respiratory psychophysiology, cerebral hemodynamics, and metabolic efficiency. The mathematical model mitigates traditional heuristic limitations through the implementation of dynamic epsilon () regularization, preventing computational singularity under extreme clinical conditions. Given the current absence of absolute in vivo cohort data, the performance of the ISB is estimated via in silico Monte Carlo perturbation simulations. Overall, this manuscript serves as a mechanistic hypothesis generator and analytical blueprint. It does not contain definitive therapeutic claims, but rather provides a rigorous quantitative foundation to guide future precision Randomized Controlled Trials (RCTs).