There’s a conversation I have regularly with parents who have received an ADHD diagnosis for their child and something about it doesn’t quite fit. The child gets overwhelmed in grocery stores. They can’t stand the tag in their shirt. Loud environments send them into a spiral that takes hours to come back from. They’re not inattentive in the classic sense — they’re hyperattentive to everything, and the overload shuts them down. This child may have ADHD. But what they almost certainly have first is a sensory processing challenge — and the two are not the same thing, even though they often show up wearing the same clothes.

How Sensory Processing Works in the Nervous System

Sensory processing is how the nervous system receives, interprets, and responds to information from the environment. When this system is working well, incoming sensory information gets filtered, prioritized, and acted upon in an organized way. When sensory processing is disrupted, the nervous system loses the ability to filter effectively. Everything comes in at the same volume. A 2007 study in Pediatrics found that approximately 5–16% of children experience sensory processing difficulties significant enough to interfere with daily functioning.^[1] Critically, a significant proportion of children diagnosed with ADHD also meet criteria for sensory processing dysfunction — suggesting the two frequently overlap but are neurologically distinct.

What ADHD Looks Like at the Nervous System Level

ADHD, at its neurological core, is a dysregulation of the prefrontal-subcortical networks responsible for executive function. Sensory processing disorder, by contrast, involves disruption at the level of sensory integration — how the brain is processing and organizing the incoming sensory stream before it even gets to higher executive functions. Research published in NeuroImage found that children with ADHD and children with sensory processing dysfunction show distinct patterns of white matter organization in the brain — different circuits, different mechanisms, different interventions.^[2] Misidentifying one as the other leads to interventions that don’t fit the actual neurological picture.

The Overlap — and Why It Gets Confusing

Both ADHD and sensory processing challenges frequently share a common underlying factor: a nervous system stuck in sympathetic overdrive. The Moro reflex — a primitive startle reflex that should integrate in the first few months of life — when retained, keeps the nervous system in chronic hypervigilance. This produces both the sensory sensitivity characteristic of sensory processing dysfunction and the dysregulated arousal characteristic of ADHD. Two labels, one neurological mechanism.

Why Getting This Right Matters

If a child’s primary challenge is sensory processing, behavioral strategies designed for ADHD attention regulation won’t address it. When we look at the objective data — INSiGHT scan findings, primitive reflex assessment, patterns of sensory reactivity — we can see what’s actually driving the presentation. And when we know what’s driving it, we can address it directly. Families across Knoxville, Maryville, and Morristown are finding that this kind of precision changes the experience for their child.