Mitochondrial Dysfunction: The Cellular Bridge from Emotional Stress to Disease Onset: A Narrative Review.

Severe emotional stress constitutes a significant public-health concern associated with negative health outcomes. Although the clinical effects are well acknowledged, the specific biological mechanisms that translate emotional suffering into systemic disease remain incompletely understood. Psychological stress activates the sympathetic nervous system and hypothalamic-pituitary-adrenal axis, which directly target mitochondria and alter their bioenergetic and redox capacity. For this reason, this narrative review proposes that mitochondria serve as the primary subcellular link in the mind-body connection, as they play a pivotal role in converting neuroendocrine signals into cellular dysfunction. In particular, we focus on the concept of mitochondrial allostatic load (MALT), a framework explaining how the progressive decline in mitochondrial functions, from their initial adaptive roles in energy production, reactive oxygen species signaling, and calcium regulation, to being sources of inflammation and systemic damage, occurs when stress exceeds regulatory limits. We also, discuss how this transition turns mitochondria from adaptive responders into drivers of multi-organ disease. In subsequent sections, we examine diagnostic potentials related to MALT, including the use of biomarkers, such as growth differentiation factor 15, cell-free mitochondrial desoxyribonucleic acid, and functional respirometry. Furthermore, we evaluate mitochondria-targeted therapeutic strategies, encompassing pharmacological compounds, such as mitoquinone mesylate, Skulachev ions, and elamipretide, alongside lifestyle and psychological interventions. Here, we aim to translate MALT biology into clinical applications, positioning mitochondrial health as a target for preventing and treating stress-related disorders. We propose that MALT may serve as a quantifiable bridge between emotional stress and somatic disease, enabling future precision medicine strategies integrating mitochondrial care.