Anxiety is the diagnosis adults with ADHD most often receive first. Sometimes it is correct. Sometimes it is correct and incomplete. And sometimes it is the only diagnosis anyone made, for years, while the thing generating the anxiety went unexamined.
The two are genuinely hard to separate, and the reason is not that clinicians are careless. It is that the surface presentation overlaps almost completely.
How Often the Two Travel Together
A 2026 meta-analysis pooled 58 case-control studies covering 18,821 adults, 5,595 of them with ADHD. Adults with ADHD reported substantially higher anxiety symptoms than adults without, with a pooled effect of Hedges's g 0.77 and a confidence interval running from 0.638 to 0.901.1
Two caveats belong with that number. Heterogeneity across the studies was high, meaning they disagreed with one another more than sampling error alone would explain, and the authors found some evidence of publication bias. The direction of the finding is not in doubt. The precise size of it is less settled than a single figure suggests.
Prevalence estimates tell a similar story with wider error bars. A systematic review comparing adults with and without ADHD found anxiety disorder prevalence ranging from 4.3% to 47.1% in ADHD samples drawn from general populations, against 0.5% to 9.5% in non-ADHD samples.2 That range is enormous, and it reflects genuinely different study methods rather than a stable fact about the world. What survives the range is the gap between the two columns.
Why Anxiety Gets Diagnosed First
Anxiety announces itself. It is uncomfortable in a way that sends people to a clinician.
Adult ADHD often does not. What it produces is a life that is harder than it should be, in ways that feel like personal failure rather than symptoms. Nobody books an appointment because their working memory is unreliable. They book because they cannot sleep, or because they feel permanently behind, or because the dread before an ordinary work task has become unmanageable.
By the time someone sits down across from a clinician, the anxiety is what is on top. It is what gets described, and it is what gets treated. This is a large part of why people who compensated well early in life tend to accumulate a long history of anxiety treatment before anyone asks a different question.
What Anxiety Looks Like When ADHD Is Driving It
There is a pattern worth noticing here, and it is a pattern rather than a test.
Anxiety generated by untreated ADHD tends to attach to consequences rather than float free. It is worry about the specific email that has gone unanswered for eleven days, the deadline that arrived faster than expected again, the thing that was forgotten and will shortly be discovered. It rises around tasks and falls once a task is done. It has a plausible external referent, because the person has in fact been missing things.
Primary generalized anxiety is more often untethered from any particular event, present in the absence of a triggering task, and resistant to reassurance even after the specific worry resolves. Someone with generalized anxiety who finishes the report tends to find a new worry waiting. Someone whose anxiety sits downstream of ADHD often feels a genuine drop.
Neither pattern is diagnostic on its own. Plenty of people have both, and in that case both descriptions will fit at once.
What ADHD Looks Like When Anxiety Is Driving It
The reverse happens too, and it is the reason a careful evaluation does not conclude ADHD simply because attention is poor.
Sustained anxiety consumes working memory. Someone running a continuous background process of threat monitoring has less capacity available for everything else, and the result looks like inattention, distractibility, and difficulty holding the thread of a conversation. It is inattention. The cause is not the same, and a stimulant is not the answer to it.
The same reasoning applies to several other conditions that imitate ADHD, and it is why the history carries more weight than the symptom list. Attention problems that began at thirty, in someone who managed fine at twelve, call for a different explanation from attention problems already visible in third grade.
Which One to Treat First
The honest answer is that there is no universal sequence, and the guidance that exists is clinical judgment rather than a rule.
A 2025 review of adult ADHD with comorbid anxiety and depression recommends prioritizing whichever condition is most severe, most functionally impairing, and least stable, then addressing the other once the first has improved.3 That is less satisfying than an algorithm, and it is what the evidence currently supports.
On the question people actually ask, whether stimulants make anxiety worse, the same review describes findings pointing in different directions. Some studies report anxiety improving on ADHD medication, some report no meaningful change, and some report worsening. There is also longitudinal data suggesting that treated ADHD is associated with lower rates of later anxiety than untreated ADHD.3 Among non-stimulant options, atomoxetine appeared to suit patients with comorbid anxiety particularly well, with the anxiety improvement seeming to follow from the ADHD improvement rather than acting on the anxiety directly.3
What that means in practice is that a stimulant trial in someone with both conditions is a question rather than a hazard to be avoided, and it is a question best answered with follow up close enough to catch the answer early. It also means non-stimulant options are worth understanding before starting rather than after something goes wrong.
What This Means If You Are In It
If you have been treated for anxiety for years, and the treatment has helped without ever quite resolving anything, that is worth taking seriously rather than filing away as a personal failure to respond.
It does not mean the anxiety diagnosis was wrong. It frequently was not. It means the question of what sits underneath it may never have been asked, and it is an answerable question. A thorough evaluation should be able to tell you which pattern fits your own history, including the real possibility that the answer is anxiety alone.
The wider picture of how adult ADHD is diagnosed, and what treatment does once it is, is covered in the guide to adult ADHD.
References
1. Hoskins JI, Gooch D, Gilligan-Lee KA. Symptoms of anxiety in adults with ADHD: a systematic review and meta-analysis of case-control studies. Journal of Attention Disorders. 2026. doi:10.1177/10870547261459712
2. Choi WS, Woo YS, Wang SM, Lim HK, Bahk WM. The prevalence of psychiatric comorbidities in adult ADHD compared with non-ADHD populations: a systematic literature review. PLOS ONE. 2022;17(11):e0277175. doi:10.1371/journal.pone.0277175
3. Fu X, Wu W, Wu Y, Liu X, Liang W, Wu R, Li Y. Adult ADHD and comorbid anxiety and depressive disorders: a review of etiology and treatment. Frontiers in Psychiatry. 2025;16:1597559. doi:10.3389/fpsyt.2025.1597559
Depression travels with adult ADHD about as often as anxiety does, and the differential is just as easy to get wrong. See ADHD and depression in adults for that overlap.
Clarity ADHD is a telehealth practice focused on adult ADHD care in Washington State offering adult ADHD evaluation and medication management, including care for co-occurring depression and anxiety. Now accepting new patients, and you can start with a free 15-minute consultation to see if it is a fit.
Book a Free 15-Minute ConsultationThe content on this website is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.