Hysteresis: Why You Can't Simply Go Back

Part 11 of Polyvagal Through the Coherence LensThe path out is not the reverse of the path in.This is hysteresis—the phenomenon where a system's state depends not just on current conditions but on its history. You can remove the stressor, eliminate the threat, restore safety. The system doesn't simply spring back to where it was before. It has been changed by the journey.This explains one of the most frustrating experiences in trauma recovery: the threat is genuinely gone, the environment is actually safe, nothing bad is currently happening—and yet the nervous system keeps behaving as if danger persists. The conditions that caused the dysregulation have resolved. The dysregulation remains.The Physics of Not ReturningHysteresis appears throughout nature. A rubber band stretched too far doesn't return to its original shape. A magnetized piece of iron doesn't demagnetize when you remove the magnetic field. A thermostat doesn't turn on at the same temperature it turned off.The nervous system exhibits the same property. Push it far enough, hold it long enough, and it doesn't simply reverse when you release the pressure. The manifold has been deformed. The attractors have shifted. The geometry itself has changed.This isn't weakness or failure. It's how physical systems work. The question isn't why the system exhibits hysteresis—it's what to do about it.Where Hysteresis AppearsAutonomic hysteresis shows up in multiple ways:Vagal tone: Chronic stress reduces vagal tone. But removing chronic stress doesn't immediately restore it. The brake has weakened, and strengthening it requires active training, not merely the absence of strain.Neuroceptive thresholds: Trauma lowers the threshold for threat detection. But safety doesn't automatically raise it back. The system learned that threats appear suddenly; it won't unlearn this just because threats stop appearing.Cardiorespiratory coupling: Sustained dysregulation weakens heart-breath coupling. But regulated conditions don't automatically restore it. The coupling must be actively rebuilt through practices that exercise the relationship.Attractor depth: Pathological states become deeply grooved through repetition. The more time spent in sympathetic lock or dorsal collapse, the more stable those attractors become. Removing the conditions that drove the system there doesn't fill in the grooves.Inflammatory markers: Chronic stress produces sustained inflammation. But removing stress doesn't immediately resolve inflammation. The immune system has its own inertia.In each case, the pattern is the same: the conditions that caused the change and the conditions that reverse it are not symmetric. Getting into a state and getting out of it require different things.The Energetics of RecoveryHysteresis has energetic implications.If the path out were simply the reverse of the path in, recovery would cost the same as deformation. But hysteresis means recovery often costs more. The system must overcome the inertia of its current state, traverse the reshaped landscape, and rebuild what was dismantled.This is why recovery feels harder than it "should." You're not just returning to a previous state—you're building a new path through a changed landscape. The map you had before doesn't match the terrain that exists now.And this is why rest alone is often insufficient. Rest removes ongoing stressors, which is necessary. But it doesn't provide the active input required to reshape attractors, rebuild coupling, and restore flexibility. The system needs both the absence of harm and the presence of repair.Implications for "Just Get Over It"Hysteresis explains why "just get over it" fails as advice.The statement assumes that removing the cause removes the effect—that once the stressor is gone, the stress should disappear. But the nervous system doesn't work that way. The effects persist because the system has been structurally changed, not because the person is choosing to hold onto them.Telling someone with autonomic hysteresis to "just relax" or "move on" is like telling someone with a stretched rubber band to "just go back to your original shape." The instruction assumes a mechanism that isn't available.This isn't an excuse for passivity. The system can change—hysteresis isn't permanent imprisonment. But change requires appropriate intervention, not mere willpower. The person needs tools that address the actual mechanism, not exhortations that assume the mechanism is different than it is.The Coherence GeometryIn AToM terms, hysteresis is the persistence of manifold deformation after the deforming force has been removed.The manifold was reshaped: Trauma, chronic stress, or sustained dysregulation changed the geometry. Curvature spiked in some regions. Attractors deepened. Topological features shifted. The landscape is different now.The deforming force is gone: The threat has passed. The stressor has ended. Safety is present. But the manifold doesn't automatically reshape.The new geometry persists: The system continues operating in the deformed landscape because that's the landscape it now has. It's not imagining the old threat—it's navigating the actual geometry that exists.Recovery requires active remodeling: The manifold must be reshaped again, this time in the direction of coherence. This requires energy, appropriate input, and time. It's construction work, not merely waiting.Hysteresis is geometric memory. The system remembers what happened to it in the shape of its state space.What This Means for RecoveryIf hysteresis is real, recovery has particular characteristics:It's not passive: Removing stressors is necessary but not sufficient. Active practices that reshape the manifold—breathwork, movement, co-regulation, rhythmic entrainment—are required.It's not immediate: Even with appropriate intervention, the system needs time to reorganize. Hysteresis involves inertia. Patience is not optional.It's not linear: The path won't be a straight line from dysregulation to coherence. There will be setbacks, plateaus, and non-linear jumps. The landscape being traversed is complex.It's not about effort alone: Trying harder doesn't overcome hysteresis. Trying appropriately—matching intervention to mechanism—is what matters. Sometimes the system needs gentleness, not force.It's not the same path: The route to coherence won't retrace the route into dysregulation. New pathways must be built. Old pathways may be abandoned rather than restored.The Irreversibility SpectrumHysteresis exists on a spectrum:Mild hysteresis: The system is slow to return but eventually does. Given enough time and safety, it finds its way back to previous patterns. No active intervention required, just patience and protection.Moderate hysteresis: The system needs help returning. Passive conditions aren't enough. But with appropriate support—therapy, practices, co-regulation—return is possible. Most trauma recovery operates in this range.Severe hysteresis: Some deformations may be permanent or near-permanent. The system can achieve new coherence, but it won't be identical to the old coherence. Adaptation rather than restoration becomes the goal.The spectrum depends on:How far the system was pushedHow long it was held thereThe individual's baseline resilienceThe presence or absence of support during and afterThe type of intervention applied during recoveryNot everything can be fully reversed. But almost everything can be worked with. The question is what kind of coherence is achievable from here—not whether the clock can be turned back.Earned CoherenceThere's a concept in attachment theory: earned security. People who had insecure attachment in childhood can develop secure attachment in adulthood—not by erasing their history but by processing it and building new patterns.The same applies to autonomic coherence. Earned coherence isn't the same as never having been dysregulated. It's coherence built through the work of recovery. It knows something that undisturbed coherence doesn't—it knows what dysregulation feels like and how to return from it.Earned coherence may actually be more robust in some ways. It has been tested. It has navigated difficult terrain. It has tools that were developed in response to challenge.Hysteresis means you can't simply go back. But what you can build going forward may be more resilient than what you had before.The Acceptance PieceWorking with hysteresis requires a particular kind of acceptance.Not acceptance that nothing can change—things can change. But acceptance that change follows the laws of the system, not the desires of the person. The nervous system will reorganize according to its actual mechanisms, not according to how quickly we want it to recover.Fighting hysteresis—demanding that the system return faster than it can, interpreting slow recovery as personal failure—adds strain without adding progress. Working with hysteresis means understanding the terrain and navigating it skillfully.The path out is not the reverse of the path in. But there is a path out.Next: Somatic Therapies as Rhythm Repair—how effective trauma treatment targets oscillatory patterns directly.Series: Polyvagal Through the Coherence LensArticle: 11 of 15Tags: hysteresis, trauma recovery, nervous system, polyvagal, resilience