I was 28 the first time someone told me their brain goes quiet.
Like... genuinely quiet. No background noise. No seventeen half-thoughts running simultaneously. No phantom to-do list narrating itself on repeat while also somehow playing a song from 2009 that I hadn't thought about in years.
Just... nothing.
I remember staring at them like they'd told me they could breathe underwater. Because I'd genuinely never experienced that. Not once. Not for a single second of my entire life.
And I thought that was normal.
What Does ADHD Internal Hyperactivity Actually Feel Like?
Imagine fifty browser tabs open at once. Now imagine you can't close any of them. Now imagine half of them are playing audio. Now imagine someone keeps opening new ones.
That's a Tuesday.
Internal hyperactivity is ADHD's best-kept secret. It's the symptom nobody sees, nobody measures, and nobody warns you about. Research suggests that while visible hyperactivity shows up in about 25% of children with ADHD, it drops to just 5% of adults. But it doesn't disappear. It just moves inward.
The fidgeting stops being in your legs and starts being in your thoughts.
Here's what it actually sounds like in my head on any given morning:
I need to send that email. What was that email about? Coffee. I should make coffee. Did I buy milk? I bought milk but did I put it in the fridge? What time is it? It feels like 10am. It's 7:15. Why did that conversation from 2019 just replay itself? I should have said something different. I'm hungry. No I'm not. Am I? What was the email about?
All of that in about four seconds. Running underneath whatever I'm actually supposed to be doing.
Every. Single. Day.
Why Does Nobody Talk About This?
Because you can't see it.
That's the brutal truth. ADHD gets diagnosed by what's visible. The kid bouncing off walls gets noticed. The adult sitting perfectly still with a war zone inside their skull? They get told they're "overthinking."
According to the NHS, ADHD symptoms in adults include restlessness and difficulty relaxing. But that single line buries what is, for a lot of us, the defining experience of having ADHD. It's not restlessness in your body. It's restlessness in your being.
And because it's invisible, it gets mislabelled. Constantly.
"You seem anxious." No. My brain is running seven parallel processes and I'm trying to look like I'm only running one.
"You're overthinking it." I'm not choosing to think this much. I can't find the off switch. There is no off switch.
"Just clear your mind." Oh, brilliant. Never occurred to me. Cheers for that.
The Meditation Problem
Let's talk about mindfulness for a second. Because I've got complicated feelings about it.
Meditation is everywhere right now. Every mental health resource, every wellness app, every well-meaning friend. "Have you tried meditation?" is the new "have you tried yoga?" and it carries the same energy of someone handing you a plaster for a broken leg.
Here's what meditation asks you to do: notice your thoughts, let them pass, return to stillness.
Here's what the ADHD brain does: notice one thought, get pulled into it, notice you've been pulled, try to return, get pulled into a thought about being pulled, notice that, accidentally start composing a song about it, remember something embarrassing from year 8, wonder if the person sitting next to you can tell you're failing at this, and then the bell rings.
I'm not saying meditation can't work for ADHD brains. Some people find it super helpful with practice. But the standard "empty your mind" instruction? That assumes you have a mind that can be emptied. Mine came pre-loaded and there's no uninstall option.
The silence is the thing that's hard. Not the sitting. Not the breathing. The silence. Because in the silence, the noise gets louder. You take away the external stimulation and suddenly the internal volume has nothing to compete with.
It's like sitting in a quiet room and realising your tinnitus has been there all along.
The Moment You Realise Other People's Brains Are Actually Quiet
This one properly... no. This one genuinely messed me up.
I remember the exact conversation. A mate described what it felt like when he had nothing to do. He said his brain just... stopped. Like a parked car. Engine off. No noise. Just sitting there.
I made him explain it three different ways because I kept thinking I was misunderstanding. He kept saying the same thing. "I just... don't think about anything."
What the f*ck.
That's when the grief hits.
Because you start doing the maths. If everyone else's brain has an idle mode and yours doesn't, then every single moment of your life has been harder than it needed to be. Every exam. Every meeting. Every attempt at falling asleep. Every conversation where you were desperately trying to focus while your brain was DJ-ing a random mix of intrusive thoughts and half-remembered song lyrics.
You've been running a marathon with a rucksack full of bricks that nobody else can see. And nobody told you the rucksack wasn't standard issue.
That realisation is a lot to sit with. If you can even sit with anything, which, as we've established, is the whole problem.
If you've felt that kind of weight after your own diagnosis, the grief of late diagnosis piece I wrote goes deeper into that feeling.
When It Gets Called Anxiety
This one's important. Because a lot of ADHD adults, especially in the UK where ADHD UK reports average NHS waiting times stretching well beyond two years as of 2026, spend years being treated for anxiety before anyone even considers ADHD.
And yeah, constant racing thoughts can be anxiety. But there's a crucial difference.
Anxious racing thoughts tend to circle. They orbit the same worry. They're fear-based. "What if this goes wrong?" on repeat.
ADHD racing thoughts are chaotic. They don't circle. They scatter. They're not about one thing. They're about everything and nothing simultaneously. You're not worried. You're just... noisy.
The distinction matters because the treatment is different. Anti-anxiety medication calms the fear response. It doesn't organise the chaos. If the problem isn't anxiety but internal hyperactivity, you can feel less frightened but still completely overwhelmed.
A 2023 study published in Frontiers in Psychology found that racing thoughts and general mind wandering are two distinct mental phenomena. Racing thoughts in ADHD were described as more pressured, faster, and less voluntary than typical mind wandering. The researchers concluded that racing thoughts represent a core feature of adult ADHD that deserves far more clinical attention than it currently gets.
So if you've been told you have anxiety and the treatment isn't quite landing... maybe the noise isn't fear. Maybe it's just your brain doing what ADHD brains do.
The Exhaustion Nobody Sees
There's a reason ADHD burnout hits so bloody hard.
You're not just tired from doing things. You're tired from thinking things. All day. Without pause. Your brain has been running at full speed since you opened your eyes and it will continue running at full speed until you finally crash, which is exactly why 2am feels like the only free time you've got.
The cognitive load of an internally hyperactive brain is enormous. You're not sitting there peacefully and then choosing to think. Thinking is happening to you. Constantly. Against your will.
It's like a computer that never goes into sleep mode. Eventually the processor overheats.
And you can't explain this to people without sounding dramatic. "My brain is loud" isn't exactly something people take seriously. But it's measurable. It's real. Neuroimaging research shows that the ADHD brain has reduced suppression of the default mode network... the system responsible for mind-wandering. Even during focused tasks, the background noise doesn't switch off. It just gets a bit quieter.
Maybe.
Learning to Live With the Volume Up
I wish I had a neat ending for this. A five-step plan to quiet the noise. But honestly? The noise doesn't go away. You learn to work with it.
Some things help. Movement helps. Music helps, weirdly, because it gives the brain something structured to latch onto instead of generating its own chaos. Background noise, coffee shop sounds, lo-fi playlists... fighting noise with chosen noise.
Medication helps some people enormously. I've heard people describe the first time ADHD medication worked as the first time they experienced genuine quiet. And they cried. Because they'd lived 30, 40, 50 years without knowing what that felt like.
But the biggest shift? Knowing it's real.
Knowing that you're not dramatic. You're not overthinking. You're not anxious. You're not "too much." Your brain is wired differently and the noise is a feature of that wiring, not a flaw in your character.
That doesn't make it easier. But it makes it make sense.
And sometimes making sense is enough to stop you adding guilt about the noise on top of the noise itself. Which, let's be honest, is what most of us have been doing for years.
If you want to understand more about how your ADHD brain processes the world, take the quiz and figure out what kind of chaotic you are. It won't make the noise quieter. But at least you'll know whose noise it is.
Yours. It's been yours all along.
