Photograph: Unsplash by Lili Kovac
Confusing attention deficit hyperactivity disorder (ADHD), with generalised anxiety disorder (GAD), has been a common mistake amongst therapists and psychologists over recent decades. A 2024 study published in the Journal of Attention Disorders showed that 17%-26% of patients with inattentive ADHD received a previous wrong diagnosis of anxiety.
Dr Laura E. Knouse, who is a clinical psychologist with expertise in studying and treating ADHD in adults, explains to us the reasons of this while giving us tips on how to spot the differences between them.
How common is it to misdiagnose ADHD with GAD (and vice versa)?
“The real answer to this question is we, unfortunately, don’t know a lot about how often these things get diagnosed or misdiagnosed, I don’t think there’s good, solid data on it.
Anecdotally, it’s definitely a thing that we see in the field. This is some years ago, but when I was training in an adult ADHD clinic, I had, for example, a patient who GAD was a better explanation for what was going on with her, and one evidence for that was that the only time she was experiencing ADHD like symptoms was when she was also in an anxious state.
I would say, as a clinician, it probably is not uncommon, but maybe we need more research about that.”
Why and how does that happen?
“On the one hand, you have a lot of symptoms overlap between these two conditions, especially things like restlessness. Some of the hyperactivity kinds of symptoms can be common to both conditions.
Most psychiatric disorders have some kind of concentration or inattention, flavour to them, right? Certainly, if we were very anxious, that’s going to interfere with your ability to concentrate on things. So, symptom overlap is the number one thing that’s important to recognise.
But then the second thing on top of that is that there truly are high rates of true comorbidity or cooccurrence between these disorders. So, you’re trying to distinguish, if they’re exhibiting symptoms of both, then it could be true comorbidity, or it could be symptom overlap, and one of them is the better explanation than the other.
The third thing is that it’s on a continuum, or on a scale, not like, “yes”, “no,” which makes it really difficult to diagnose.”
Is gender bias involved?
“We’re all humans, and we’re all prone to whatever biases there are, right? And so, I do think it’s changing, but I also think some clinicians still operate under that whole, ‘ADHD is like a hyperactive little boy.’ Also, the idea that men might express their anxiety differently, so I think you’re really on to something there.”
Have you ever misdiagnosed someone with ADHD or GAD and how did you discover your mistake if you have?
“I will say I have had people come in with an ADHD diagnosis that then, through my work, I’ve been like, I don’t think this is the best explanation. Now, that’s not saying I’m any better than anyone else diagnosing, it’s just that I think, maybe what you’re pointing to is a bigger issue: we don’t really have a good way to follow up with people whether it was right, which maybe is why the research isn’t there.”
What are the differences between ADHD and GAD that every person should know when dealing with either or both?
“The first thing is age of onset. The age of onset for ADHD is younger than the age of onset for anxiety disorders, since you should have showed symptoms before the age of 12 if you have ADHD.
One other thing I will say is that ADHD symptoms should be a little bit more like personality, it’s kind of how you always are, and the situation doesn’t really impact you as much.
Whereas, usually with anxiety disorders, the symptoms can get worse, they can wax and wane. You are really only having concentration problems when you’re in a time of high stress, unlike ADHD.”
As a specialist, what is the most common mistake someone with ADHD and GAD could do when dealing with their condition and wish for them to avoid if possible?
“It’s thinking you can avoid the problem and it’s going to get better, because what’s challenging is that the feeling of anxiety is unpleasant, and whatever causes that anxiety to arise, you’re going to want to avoid it or back away from it, right? And sometimes that’s okay, but other times it keeps you from being able to engage with the people or do the things in your life that would really enhance it or help you meet your goals.
I want to be quick to say I’m not blaming the person because it’s what you would naturally do when you feel that anxiety, but I would just want people with both ADHD and GAD, to be aware that there are really great research supported treatments for both conditions, and that includes both medications, but also cognitive behavioural therapies.”