ADHD in adults: signs we have put down to character for decades

“I know how. I know exactly what I need to do. I just don’t do it.”

That is how someone once described their mornings to me: bills on the table that had been waiting for three weeks, fifteen open browser tabs, a promise to a colleague he had forgotten, and a clock that once again told him he would be late. He wasn’t lazy. He worked more than most people around him, just differently — in bursts, late at night, right before a deadline, with enormous energy for things that caught his interest and almost none for those that didn’t. All his life he had heard the same thing: “If only you tried a bit harder.”

For many adults who come to talk about anxiety, exhaustion or difficulties in a relationship, there is something else behind that sentence. Sometimes it is ADHD — attention deficit hyperactivity disorder — that nobody noticed, because the child was well-behaved, clever or quiet enough. I don’t make diagnoses; that is the work of a psychiatrist or a clinical psychologist. What I can do is describe what ADHD looks like when it grows up, and why we mistake it for character for so long.

What ADHD is — and what it isn’t

ADHD is a neurodevelopmental difference: it begins in childhood, it affects how the brain regulates attention, movement, impulses and emotions, and for many people it does not disappear in adulthood. It does change shape, though. The child who couldn’t sit still becomes the adult who can’t sit through a meeting without restlessness running down their legs. The child who kept forgetting their slippers becomes the adult who keeps forgetting deadlines.

What ADHD is not: it is not a lack of intelligence, it is not the result of bad parenting, and it is not a recent fad. The international consensus statement published in 2021 by the World Federation of ADHD brought together more than two hundred research-backed conclusions — from heritability to the consequences untreated ADHD has in everyday life. It is one of the most thoroughly researched conditions in psychiatry.

Because the word “disorder” bothers many people, many now speak of neurodivergence — of brains that work differently from the average, not necessarily worse. Both are true at once: ADHD brings real difficulties that deserve to be taken seriously, and it also brings traits that are valuable in the right environment. I wrote about this duality among people who have founded their own business in ADHD and entrepreneurship: a gift and a burden at once.

Why we overlook it in adults for so long

When the World Health Organization looked at how common ADHD is among adults in ten countries, it estimated that on average around 3.4 per cent of adults meet the criteria (Fayyad et al., 2007). There were differences between countries, but the message is clear: this is a relatively common condition. A large share of these people never received a diagnosis.

There are several reasons. The first is the picture we carry in our heads: a boy climbing over the desks. Anyone who wasn’t like that — because she was a girl, because they daydreamed instead of jumping about, because they were clever enough to make up for whatever they had missed — slipped past. The second reason is that adults cover up their difficulties for a long time. They invent systems, reminders, requests for extended deadlines, a partner who keeps the calendar. The third reason is that in adults other struggles are often in the foreground — anxiety, depression, burnout, sleep problems — and these hide what was there before.

When the DSM-5 diagnostic manual was published in 2013, it took into account that ADHD changes over the years: for adults it requires fewer pronounced symptoms than for children, but it insists that symptoms were present before the age of twelve and that they disrupt functioning in several areas, not only at work or only at home. This matters, because it distinguishes ADHD from a period when a person is simply overloaded.

Signs we put down to character

In adults, ADHD rarely looks like physical restlessness. Far more often it looks like something that other people — and the person themselves — call personality. Here are some patterns people describe when they look back:

• “You’re so scatterbrained.” Keys, phone, glasses, a thought in the middle of a sentence. Not the occasional forgetfulness we all know, but a pattern that persists for years.
• “You leave everything to the last minute.” A deadline two weeks away doesn’t exist. A deadline tomorrow switches on all the lights at once.
• “You start a hundred things.” Enthusiasm for a new hobby, course or project that fades after a few weeks — not because the person doesn’t care, but because the novelty has lost its pull.
• “You keep interrupting.” The thought is here now and in five seconds it will be gone, so you say it before the other person has finished.
• “You overreact.” Anger that flares up and quickly dies down, hurt at a small remark, tears that come before you can stop them.
• “You can do it when you want to.” This may be the most painful sentence, because it seems true. With an interesting task, a person with ADHD can stay focused for hours. That is exactly why others conclude that everything else is a matter of willpower.

None of these signs means anything on its own. We are all late sometimes and we all procrastinate. What sets ADHD apart is persistence, breadth and cost: a pattern that has lasted since childhood, shows up at work, at home and in relationships, and costs the person more than it should.

The gap between knowing and doing

The psychologist Russell Barkley, one of the most influential ADHD researchers, put into words an idea that people with ADHD often recognise as a precise description of their lives: ADHD is not a disorder of knowing what to do, but a disorder of doing what you know. The knowledge is there. What gets stuck is the step from intention to action at the right moment.

We call this set of abilities executive functions: planning, getting started, holding information in mind, switching between tasks, inhibiting impulses and regulating emotions. They are like the conductor of an orchestra. The musicians can be excellent, but if the conductor doesn’t show them when to come in, you get noise.

Barkley emphasised one more thing: in ADHD, the sense of time is particularly weakened. The future doesn’t feel real until it is very close. That is why the advice “just start earlier” doesn’t work — not because the person doesn’t understand it, but because a distant deadline doesn’t set anything off in the body. What helps is anything that brings the future into the present: visible clocks, interim deadlines, someone working alongside you.

The emotional side that rarely gets mentioned

Emotions are barely mentioned in the diagnostic criteria, yet in the daily lives of people with ADHD they are often front and centre. A review by Philip Shaw and colleagues from 2014 showed that difficulty regulating emotions is common in ADHD and cannot be explained solely by the other conditions that often accompany it. Emotions come faster, they are stronger and they take longer to settle.

This has consequences in relationships. A partner experiences an outburst they don’t understand, and half an hour later the person with ADHD feels ashamed of a reaction they couldn’t stop. I have also described how emotions are regulated, and why this is harder for some people, in the knowledge base under emotion regulation.

When you explain your difficulties to yourself

When someone who has ADHD doesn’t know they have it, they explain their difficulties to themselves. And the explanation closest to hand is almost always a moral one: I’m lazy, I’m irresponsible, I’m not good enough. Over the years this explanation hardens into an inner critic that doesn’t rest even when everything is going well.

Often something else joins in: the person starts measuring their worth by how much they get done, and because they always get “too little” done, they never reach the feeling of being enough. I have written more about this pattern in Worth only as much as you get done. Beneath it there almost always lies shame: the emotion that whispers “There is something wrong with me”.

A conversation like this might sound something like this (composite, not a real person):

“I forgot the parents’ evening again. My wife just looked at me.”
“What did you tell yourself in that moment?”
“That I’m hopeless. That I’ll never learn.”
“How many years have you been hearing that sentence?”
He thinks. “For as long as I can remember. First from my teacher, then from my mother, now from myself.”
“What if it isn’t that you don’t want to learn, but that your memory for arrangements works differently — and that you need a different route, not more effort?”
He is silent for a long time. “That would be … less shameful.”

This shift — from “what’s wrong with me” to “how do I work and what do I need” — is often the first step. It can happen even before a diagnosis, but it doesn’t replace one.

When it isn’t ADHD

Because the signs of ADHD are so ordinary, it is important to say the opposite as well: the vast majority of distractibility is not ADHD. Social media is full of short videos in which almost everyone recognises themselves, and that has a good side — people start asking questions. But it also has a bad side, because other questions get closed too quickly.

Things that can look similar to ADHD include:

• anxiety, which occupies the mind and takes away concentration;
• depression, in which energy, memory and the will to get started all drop;
• burnout, which makes every task harder — more on this in Burnout is not laziness;
• lack of sleep, which on its own seriously weakens attention;
• physical conditions, hormonal changes, some medications or substance use;
• a life that is simply too much — a young parent with two jobs doesn’t necessarily have ADHD, they may just be tired.

The key difference is timing: if the difficulties appeared in recent years and weren’t there in childhood, ADHD is less likely and the answer probably lies elsewhere. Often, though, conditions overlap. That is exactly why self-diagnosis isn’t enough, and why it makes sense for someone who can tell one from the other to look at the whole picture.

Who makes the diagnosis

ADHD in adults is diagnosed by a psychiatrist or a clinical psychologist, based on a conversation, questionnaires, information from childhood and often also a conversation with someone who knows you well. I explained who may do what in this process in Who may diagnose, who may prescribe, and who leads the process, and the practical route is covered in Adult ADHD assessment in Slovenia: where to turn and what to expect.

The European expert consensus on adult ADHD (Kooij et al., 2019) stresses that an assessment is not just a matter of counting symptoms. It has to cover the whole life story, accompanying difficulties and the way symptoms affect functioning. That is why it helps to bring whatever you have: old school reports with teachers’ comments, memories from parents or siblings, examples from work.

As for treatment: decisions about medication are made by a doctor, together with you. For many adults medication helps, for some less so, and it doesn’t resolve everything that has piled up over years without an explanation. That is why it is often combined with other support.

This also holds true: a diagnosis is a map, not a name for you. It shows where the bends in the road are, but it doesn’t say who you are or where you are going. And if the conclusion isn’t ADHD, that doesn’t mean you imagined your difficulties — it means the answer lies elsewhere and is worth looking for further.

Exercise: a map of where you get stuck

This exercise isn’t a test and won’t tell you whether you have ADHD. It helps you gather observations that are useful whatever the answer — for a conversation with a doctor, with your partner or with yourself.

1. Choose one week. Every evening, write down three moments when something didn’t go the way you wanted: being late, an unfinished task, a forgotten arrangement, an outburst.
2. Next to each one, note what happened just before. Not why you are “bad”, but what was going on around you: noise, tiredness, unclear instructions, a boring task, a sudden switch.
3. Also write down one moment when things went well. What was different? A deadline, another person, interest, movement, music?
4. At the end of the week, look for a pattern. Which conditions keep coming up when you get stuck, and which when things go well?
5. Choose one condition you can change this week — a reminder on the door, working alongside someone else, a shorter interim deadline. And notice how your inner voice changed when you described getting stuck as conditions rather than failings.

If your notes reach far back into childhood and appear everywhere, take them with you to your GP. If this exercise makes you painfully aware of how harshly you speak to yourself, you may find Self-compassion instead of self-criticism helpful.

What therapy can offer

Psychotherapy doesn’t “cure” ADHD and it isn’t a substitute for an assessment or medication. However, a study by Steven Safren and colleagues (2010) showed that for adults who were already taking medication and still had marked difficulties, cognitive behavioural therapy brought more improvement than relaxation exercises with psychoeducation. In other words: skills can be learned, and that helps.

In relational family therapy, in which I am training, we look at one more layer — relationships. ADHD doesn’t live in just one person. It lives in a partnership where one person takes on more and more tasks and grows tired, while the other is increasingly criticised and withdrawn. It lives in a family where the parents may have had similar traits that nobody ever named. When these patterns are recognised, both blame and shame often ease. Part of this work can be the 90-minute session A Look into the Past, in which we use a genogram to see how similar patterns have been passed down through generations. I also work with English-speaking clients in person in Ljubljana.

And finally: therapy can be a place for everything that comes after a diagnosis. For many adults a late diagnosis brings a mixture of relief and sadness, which I wrote about in Late ADHD diagnosis: relief and grief at once.

What to remember

• ADHD begins in childhood and for many people continues into adulthood, but it changes shape — from restlessness in the body to restlessness in the mind, from forgotten slippers to forgotten deadlines.
• We often put the signs of ADHD in adults down to character: laziness, irresponsibility, oversensitivity. Behind them there is often a difficulty with executive functions, not with willpower.
• Distractibility has many causes — anxiety, depression, burnout, lack of sleep. If there were no difficulties in childhood, the answer probably lies elsewhere.
• A diagnosis is made by a psychiatrist or a clinical psychologist; decisions about medication are made by a doctor.
• Whatever the diagnosis, you can start today to describe where you get stuck as conditions you can change, not as failings you are to blame for.