ADHD Unpacked › What is ADHD?
What it actually feels like from the inside — and what the science says is going on underneath.
For most of my life, I thought I just wasn't trying hard enough. Everyone else seemed to be able to sit down, focus, get things done — and I'd start three things at once, finish none of them, and spend the rest of the day feeling vaguely guilty about it. The word ADHD didn't really land for me. I thought it meant hyperactive kids who couldn't sit still. I could sit still. I just couldn't make my brain do what I needed it to do.
When I finally got a diagnosis, one of the first things I read described ADHD not as a lack of attention, but as an inconsistency of attention — and something clicked. I didn't have a problem paying attention. I had a problem controlling where my attention went. I could spend four hours completely absorbed in something that interested me, and be completely unable to spend twenty minutes on something that didn't. That wasn't laziness. That was my brain working exactly as it was built to.
Understanding that changed everything. Not because it made things easier overnight — it didn't — but because it gave me a frame. I wasn't broken. I was wired differently. And once I understood how I was wired, I could start working with it instead of constantly fighting against it.
ADHD — Attention Deficit Hyperactivity Disorder — is a neurodevelopmental condition, meaning it relates to how the brain develops and functions rather than being something that happens later in life. It's one of the most researched conditions in psychiatry, and the evidence base is substantial.
At its core, ADHD involves differences in the brain's executive function system — the part responsible for planning, prioritising, starting tasks, managing time, and regulating emotions. The prefrontal cortex, which handles much of this work, develops more slowly in people with ADHD and functions differently throughout life. Two key neurotransmitters — dopamine and norepinephrine — are also involved. These chemicals help regulate attention, motivation, and impulse control, and in ADHD brains they don't work in quite the same way.
ADHD is highly heritable — it runs strongly in families — and it affects people across all backgrounds and intelligence levels. Contrary to the stereotype, it's not just a childhood condition: the majority of children with ADHD continue to experience it into adulthood, even if the presentation changes. And many adults, particularly women, are diagnosed late having spent years developing coping strategies that masked the condition from the outside.
A clear, UK-focused overview of what ADHD is, the different types, and how it's diagnosed.
Read on ADHD UK →Jessica McCabe's brilliant introduction to ADHD — warm, accessible, and a great first watch.
Watch on YouTube →The official UK clinical guidance. Dry but authoritative — useful if you want to understand the medical picture.
Read on NICE →