ADHD or anxiety? How to tell them apart

“I spent two years working on my anxiety. The worry really has settled, I sleep better, work doesn’t grip me the way it used to. But I still can’t read a chapter to the end. On holiday, when I had nothing at all to worry about, I left my passport at the hotel.”

That sentence carries an important question. If anxiety was what was getting in the way of concentration, why didn’t concentration come back once the anxiety eased? Perhaps because something else was there in the background. Or because both things were there all along.

At first glance, ADHD and anxiety look very alike: restlessness, trouble concentrating, poor sleep, irritability, procrastination. That is why they are easy to confuse — and why someone can spend years treating one while the other goes unrecognised. In this post I’d like to offer a few questions that help you see the difference. But I don’t make diagnoses, and neither can this post: ADHD and anxiety disorders are assessed by a psychiatrist or a clinical psychologist.

Why they are so easy to confuse

If you compare the criteria for ADHD and for generalised anxiety in the diagnostic manuals, you’ll notice that some points almost overlap. The signs listed for generalised anxiety disorder include restlessness or feeling on edge, being easily tired, difficulty concentrating or the mind going blank, irritability and disturbed sleep. Anyone who reads that list with experience of ADHD may easily recognise themselves in it.

At the same time, the two often occur together. In a large American study led by Kessler and colleagues, almost half of adults with ADHD had also had an anxiety disorder in the past year. That means the question is often not “one or the other” but “how much of each” — and which came first.

This is why the American diagnostic manual DSM-5 explicitly requires, for ADHD, that the symptoms are not better explained by another mental disorder, such as an anxiety disorder. That is not a bureaucratic footnote. It is a warning that the two pictures are so close they have to be told apart deliberately.

The first question: where does your attention go?

When people with anxiety can’t concentrate, their attention usually doesn’t scatter at random. It gets caught by worry. You are reading a report while your head replays the conversation with your boss that awaits you tomorrow. You are watching a film while thinking about test results that haven’t come back yet. Michael Eysenck and colleagues described this in attentional control theory: anxiety pulls attention towards possible threat and uses up resources you would otherwise have for the task in front of you.

With ADHD the picture is different. Attention doesn’t necessarily go to something threatening — it goes to something else. To a sound from the street, an interesting thought, whichever tab happens to be open. People with ADHD often describe that what gets in the way of a boring task is not fear, but the simple fact that the task “doesn’t grip”.

A simple question you can ask yourself: when I lose the thread, what am I thinking about? If the answer is almost always “what might go wrong”, that points in a different direction than if the answer is “all sorts of things”. I wrote about how worry spins around itself in “What if …”: why the brain would rather predict a hundred disasters than one calm day.

The second question: since when?

ADHD is a neurodevelopmental difference. That means it doesn’t arrive suddenly in adulthood. According to the DSM-5 criteria, some of the symptoms must have been present before the age of twelve, even if nobody named them at the time. In adults with ADHD, the same remarks often recur in old school reports — “could achieve more if he paid attention”, “daydreams”, “forgets his homework”.

Anxiety can also reach back into childhood, but its course more often shifts with life circumstances. It appears with a loss, a move, a new job, the birth of a child, settles, and comes back again. If your concentration problems only appeared after some major stress, that doesn’t rule out ADHD — the stress may simply have exposed something you had been compensating for — but it is an important piece of information for the assessment.

So before a possible assessment, it’s worth digging out old school reports or talking to someone who knew you as a child about what you were like. If you’re interested in how ADHD in adults often hides behind “character”, read ADHD in adults: signs we have put down to character for decades.

The third question: what happens when things are calm?

This may be the most telling question of all. Think of a time when there was no great pressure — a holiday, the summer, a quieter month at work. What happened to your concentration?

With anxiety, concentration often improves when things calm down. When the worry is gone, there is more room in your head. With ADHD, the opposite can happen: without a deadline pressing, it is even harder to get started. Many people with ADHD describe working best under pressure — not because they like it, but because pressure brings a drive that otherwise isn’t there.

Restlessness is similar. Anxious restlessness is tense: a clenched jaw, shallow breathing, a sense that something is about to happen. It usually eases when circumstances calm down. Restlessness in ADHD is often more like a need for movement or change — a leg jiggling under the table, a hand reaching for the phone, the urge to stand up in the middle of a meeting. It isn’t necessarily unpleasant and it isn’t tied to fear. Many describe it as something that was always there, even on the loveliest holidays.

Sleep tells its own story too. When anxiety won’t let you fall asleep, your thoughts usually circle around worries: what tomorrow will bring, what I said wrong, what if. People with ADHD often describe their head only really waking up in the evening — not out of fear, but because everything finally goes quiet and it is the turn of ideas, plans and interesting thoughts. The result is the same in both cases: tiredness the next day. But the content of the wakefulness is different, and that is exactly what matters for an assessment.

The sentence at the start of this post describes precisely this: the anxiety went, but the muddle stayed. That is not proof of ADHD. But it is something worth telling a doctor — in exactly those words.

Procrastinating out of fear, or procrastinating without a spark

Both states know procrastination, but it comes from different places. With anxiety, you avoid a task because you are afraid of what it will reveal: that you won’t be good enough, that someone will be displeased, that you will make a mistake. Avoidance brings brief relief, and so it repeats. More about this mechanism in Anxiety and avoidance: why avoiding helps you today and harms you tomorrow.

With ADHD, procrastination is often linked to executive functions — the way the brain plans, starts and sustains a task. A person knows they have to do the task, they are not afraid of it, and still they can’t begin. As if the engine were running but the gear won’t engage.

In reality the two often intertwine. Someone with ADHD who has missed deadlines for years eventually develops a fear of tasks too — and then procrastinates for both reasons at once. That is why the question “why do I procrastinate?” is often more useful than “do I procrastinate?”.

When anxiety is a consequence of ADHD

For many adults with ADHD, anxiety is not a separate problem but a response to living with unrecognised difficulties. If you have spent your whole life forgetting, running late and hearing that you don’t try hard enough, you learn to live on alert. You check everything three times. At night you go over what you’ve forgotten this time. Tension becomes the price you pay so that nothing slips through.

This matters because it changes how you see yourself. If anxiety is a response to years of slips, it isn’t a sign that you are “too sensitive”. It is an understandable survival strategy that has become too costly. I wrote about how everything can look fine on the outside while an alarm rings inside in High-functioning anxiety: in control on the outside, an alarm ringing inside. In women this pattern is especially common, because ADHD stays hidden for longer — that is the subject of ADHD in women: why it goes unnoticed until adulthood.

This is how a conversation about it might sound in therapy (a composite, not a real person):

“I always thought I was just an anxious person. My mum was like that, I’m like that.”
“What worries you most when you lie in bed at night?”
“That I’ve forgotten something. That I’ll mess something up at work again tomorrow.”
“And does that happen?”
“Often. That’s why I check.”
“So the worry didn’t come from nowhere. It protects you from something that really happens.”
A long silence. “I’ve never heard it put like that.”

Why the difference matters for getting help

Telling them apart is not an academic question. It determines what kind of help makes sense. For anxiety, psychotherapeutic approaches and medication are both well researched; I wrote about what the research shows in Therapy or medication for anxiety: what the research shows. With ADHD, what matters is understanding how you function, adjusting your environment, learning strategies, psychotherapy and, for some people, medication.

When both are present, the order and type of treatment is a matter of professional judgement. Medication that helps with one difficulty can affect the other in different ways — which is why it is decided by a doctor who knows the whole picture, together with you. I won’t give any advice here about specific medication; what matters is that your doctor hears about everything you notice, including what seems unimportant to you.

And one more thing: even if it turns out to be “just” anxiety or “just” ADHD, the explanation you’ve been given may not account for everything. An assessment is not a life sentence. If, after treatment, one difficulty eases and the other remains, it makes sense to open the question again.

Exercise: a five-day attention diary

This exercise won’t tell you what you have. But it will help you gather information you often can’t recall during an assessment — and at the same time you begin to observe yourself with curiosity instead of judgement.

1. For five days, carry a slip of paper or a note on your phone. Every time you notice you’ve lost the thread of a task, write down the time and what you were doing.
2. Write down where your attention went. Was it a worry (“what if …”), or did it drift towards something else (a sound, a thought, your phone)? One word is enough.
3. Rate the tension in your body from zero to ten. A clenched jaw, shallow breathing, unease in your stomach — or none of these?
4. Rate how interesting the task was, also from zero to ten.
5. On the fifth day, read through your notes. Is losing the thread more frequent when tension is high or when interest is low? Or both? Take your notes with you when you talk to a doctor about it.

If, during the exercise, you notice your thoughts going round in circles, the concept of rumination may help — an explanation of why the brain chews things over so persistently.

Where this distinction breaks down

The questions I’ve described are an aid to reflection, not a test. And even as an aid they have limits. First, ADHD and anxiety often occur together, so searching for the “right” answer can lead to a dead end — the answer may be both.

Second, similar concentration problems can also be caused by depression, the after-effects of trauma, chronic sleep deprivation, physical illness (thyroid conditions, for example), hormonal changes, alcohol or some medications. Someone after a traumatic experience may be restless and distracted because of constant vigilance, not because of ADHD or generalised anxiety. That is why it’s good for a doctor to rule out physical causes first.

Third, self-assessment has blind spots. People who have compensated for a long time often underestimate how much effort they put in, while others, after watching online videos, overestimate how many signs they have. This, too, is why an assessment belongs with a specialist who can ask you what you wouldn’t think to ask yourself.

What can help in therapy

As a marriage and family therapist in training under supervision, I don’t make diagnoses or prescribe medication. But together we can look at what keeps repeating in your life. What were the stories about you in your family — were you “the worried one” or “the scatterbrain”? Who in the family took on responsibility for order, and who needed it? Relational family therapy looks at exactly these patterns: how emotions and roles are passed from generation to generation and how we carry them into our relationships today.

Therapy can also be a place where anxiety is not treated as an enemy but as a message that needs to be heard. And where you have time to consider calmly whether it would make sense to seek an assessment from a psychiatrist or clinical psychologist — if your doctor hasn’t already suggested it. I also work with English-speaking clients, in person in Ljubljana.

What to remember

• ADHD and anxiety share many signs — restlessness, trouble concentrating, poor sleep, procrastination — and often occur together.
• Three questions help: where does your attention go, how long have the difficulties been there, and what happens when life is calm.
• Anxiety can also be a consequence of years of unrecognised ADHD — an understandable response, not a character flaw.
• If confusion and forgetfulness don’t ease after anxiety has been treated, it is worth telling your doctor.
• A diagnosis is made by a psychiatrist or clinical psychologist; medication is decided by a doctor, together with you.