The concept of feedback loop appears across the depth-psychology corpus in registers ranging from the neurophysiological to the systemic-psychological, occupying a position of structural importance that few single terms can claim. At the biological level, authors such as Levine, Porges, and Craig invoke negative feedback as the foundational regulatory logic of the autonomic nervous system — the thermostat metaphor serving as a pedagogical bridge between control-engineering and somatic experience. Levine in particular moves beyond the mechanical analogy to argue that psychic life exhibits emergent, creative self-regulation that transcends simple homeostatic oscillation. Lewis extends this reasoning into developmental neuroscience, showing that self-organizing systems amplify their own patterns through iterative feedback in ways that produce habit and addiction. Schwartz, working from Internal Family Systems, translates the concept into intrapsychic systems language: reinforcing feedback loops between managerial and firefighter parts explain how protective dynamics escalate rather than resolve. Verdejo-Garcia applies the construct to the distorted bodily-signal processing that characterizes addictive states. A persistent tension runs through the literature between negative feedback — stabilizing, homeostatic, corrective — and reinforcing (positive) feedback — amplifying, potentially pathological, yet also generative. The term thus stands at the intersection of cybernetics, affective neuroscience, and systems-oriented psychotherapy, constituting a conceptual hinge between body, brain, and relational field.