Many adults who are diagnosed with ADHD later in life describe a similar story. They spent years working on anxiety, the support genuinely helped, and yet something underneath never quite shifted. ADHD and anxiety can be surprisingly hard to tell apart, and they also turn up together far more often than most people realise.
Why ADHD and anxiety get mixed up
On the surface, the two can look almost identical. Both can make it hard to concentrate, both can affect sleep, and both can leave you feeling restless, overwhelmed and behind on things that seem easy for everyone else. Researchers reviewing the evidence on adult ADHD have noted that these overlapping symptoms make diagnosis genuinely tricky, and that inattentive presentations, particularly in women, are often mistaken for anxiety or depression (Fu et al., 2025).
The difference usually lies in the reason behind a symptom rather than the symptom itself.
Some ways they can differ
Concentration: with ADHD, attention tends to drift toward whatever is more interesting, while with anxiety it gets pulled toward worries
Starting tasks: ADHD procrastination is often about a task feeling impossible to begin, while anxious avoidance is usually about fear of getting it wrong or being judged
Restlessness: ADHD restlessness often feels like a need to move, while anxious restlessness tends to feel like tension held in the body
Timeline: ADHD traits have usually been there since childhood, even if they were masked, while anxiety can appear or worsen at particular points in life
When the pressure lifts: anxiety often eases once a stressful period has passed, while ADHD challenges tend to stay fairly constant across holidays, jobs and seasons of life
None of these are hard rules, and plenty of people will recognise themselves on both sides of the list.
When it's both
For many people, it isn't one or the other. Research suggests that up to half of adults with ADHD also experience an anxiety disorder (Fu et al., 2025). With more than a million Australians living with ADHD (AADPA, 2022), that adds up to a lot of people managing two things at once, often without realising it.
The connection makes sense when you think about daily life with undiagnosed ADHD. Missed deadlines, forgotten appointments, a constant feeling of running behind and years of being told to just try harder can all build a steady background hum of worry. Over time, that worry can become a problem in its own right.
This is why getting the full picture matters so much. If anxiety is treated on its own while ADHD goes unrecognised, some strategies may not land as well as they could, and people can end up blaming themselves for not trying hard enough.
What an assessment can tell you
A comprehensive ADHD assessment looks at your history, how you manage across different parts of your life, and whether things like anxiety, depression or trauma are also playing a part. The aim is to understand how your brain works so that the support you get actually fits, rather than simply handing you a label.
At Valentia Health, our psychologists conduct ADHD assessments for children from age six, teens and adults, with a neurodiverse-informed approach throughout. We're interested in your strengths as well as your challenges, and we look at anxiety and mood alongside ADHD rather than in isolation. Whatever the assessment shows, we can keep supporting you afterwards with therapy shaped around what's really going on.
Signs it might be worth looking deeper
You might consider an assessment if any of these sound familiar:
Anxiety support has helped, but focus, organisation or follow-through still feel like an uphill battle
You've struggled with attention, time or restlessness for as long as you can remember
Most of your worry centres on falling behind, forgetting things or letting people down
A child or relative has recently been diagnosed with ADHD and some of it sounds a lot like you
You feel worn out by the constant effort of holding everything together
Wondering about this is a really common and healthy thing to do. Asking the question doesn't commit you to anything, and for many people it brings a real sense of relief.
Taking the next step
If any of this sounds like you or someone you love, we'd be glad to talk it through with you. You can find out more about our ADHD assessments and therapy at valentiahealth.com.au, or call us on (07) 3544 6748 to book in. We see clients at our Taringa clinic, close to Toowong and Indooroopilly, and by telehealth across Australia.
References
Fu, X., Wu, W., Wu, Y., Liu, X., Liang, W., Wu, R., & Li, Y. (2025). Adult ADHD and comorbid anxiety and depressive disorders: a review of etiology and treatment. Frontiers in Psychiatry, 16. https://www.frontiersin.org/articles/10.3389/fpsyt.2025.1597559/full
Australian ADHD Professionals Association (2022). Australian Evidence-Based Clinical Practice Guideline for ADHD. https://adhdguideline.aadpa.com.au/
This post is for general informational purposes and is not a substitute for professional psychological advice. If you are in crisis, please contact Lifeline on 13 11 14 or call 000.