When the response is bigger than the trigger.
A neurotypical nervous system tends to respond to emotional input proportionally — like a faucet. Turn it slightly, get a trickle. Open it wide, get a stream.
An AuDHD nervous system often responds more like a fire hydrant. The valve is either closed or it is fully open. There isn't always a middle.
What this means in real life
- A small criticism can feel devastating to them even when you meant it gently.
- A change of plans can trigger a response that seems disproportionate.
- They may feel emotions more intensely and have less automatic ability to regulate them.
- After a big emotional response they're often exhausted — the hydrant has emptied.
Signs you're seeing this in daily life
- Emotional responses that seem disproportionate to the trigger.
- Quick escalation followed by genuine remorse.
- Sensitivity to criticism, tone of voice, or perceived rejection.
- Emotional exhaustion after busy or stressful days.
Clinical notes
- Flooding is not oppositional or manipulative. It is autonomic.
- Recalling events may seem like catastrophising or magnification.
- Interventions that work often focus on recognizing early flood cues (increased heart rate, racing thoughts, overwhelm), post-flood repair rather than only pre-flood prevention, and reducing shame — which reduces flood frequency over time.
- Avoid behavior charts that punish flooding. Reward post-flood repair instead.
- This is a different nervous system architecture — one with a less-modulated emotional pathway, often compounded by interoceptive differences (not noticing the build-up until it has already arrived).
When a client describes a response that seems disproportionate, the inside-out question isn't why are they so reactive? It's what is the wiring underneath this, and what does this nervous system need to find its way back to baseline?
Try it in session: give the client the language. "I'm hydrant right now" reduces shame and improves communication faster than almost any other intervention.