Mental health · Aug 14, 2026
My mind never stops. Is this ADHD or anxiety?
A half-used blister pack, with someone else's name on the pharmacy label, has become a common way for a concentration complaint to reach my office. It usually arrives with the question already formed, whether this is ADHD. Here is what I look at before I answer.
She put a half-used blister pack on the desk, with someone else's name on the pharmacy label. She said it plainly: half a tablet on study nights, a whole one the night before the civil service exams, and she had been doing this for eighteen months. She had no prescription. A classmate at her exam prep course did. What she wanted from the appointment was the stamp, the diagnosis that would explain why she could not study after work, and the prescription that would make legal what she was already doing.
I told her that scene has statistics behind it. A systematic review led by Safia Sharif and colleagues, at the University of Hertfordshire, in the United Kingdom, gathered in 2021 the studies on stimulant use as a study aid among university students, and records that the people who use them tend to have no diagnosed disorder, looking for more alertness, concentration or memory, with the substances coming largely from friends and family. A review published two years later by Sebastian Magnotti and colleagues adds the detail that usually surprises whoever arrives this way, and that I repeat every time the blister pack lands on the desk.
Stimulants do not improve cognitive performance in people who do not have ADHD. The review says it in so many words, that cognitive enhancement is the main reason for use and that it does not occur in healthy adults. What a person feels when she takes one is something else. Less sleepiness, more drive, the sense of getting somewhere. The sense of getting somewhere and actually getting there are not the same measure.
A full mind is not a scattered mind
When she described her routine, the thing that changed the whole appointment showed up. For every week of studying she built a detailed schedule, with the subjects separated by color, the unexpected already accounted for, and a backup plan in case the day slipped. She printed more material than she needed, always arrived early, and spent the night before with her mind spinning and no way to shut it off.
That is not the shape of ADHD. A person living with sustained attention deficit struggles precisely to build and hold that kind of meticulous planning, which demands working memory and sequencing. Her complaint was that she could not study, and the reason was not a mind too empty. It was a mind too full. A full mind and a scattered mind arrive with the same sentence, I cannot concentrate, and they are not the same thing.
It is worth saying that adult ADHD is real, common and undertreated. The American national survey led by Ronald Kessler, at Harvard, estimated in 2006 a current prevalence of adult ADHD of 4.4%, with high comorbidity with other disorders and most cases untreated. I am not saying it gets overdiagnosed. I am saying the same complaint fits two different pictures, and the difference changes the whole treatment.
It worked with a friend's tablet, so it must be ADHD?
That reasoning sounds logical and is not. If a stimulant does not raise performance in someone without the disorder, then feeling better does not separate who has it from who does not. Plenty of people without ADHD feel they performed well, because they slept less and stayed more awake, and that is not the same as correcting a deficit.
In her case there was also a sign pointing the other way. Her response to the stimulant was weaker than you would expect from someone living with the disorder, and it is that lukewarm response, and not the improvement, that usually makes me suspect the problem is something else.
I need to say something that deliberately complicates what I have just simplified. It is not always one or the other. The same American survey records that adult ADHD comes with other disorders very often, and anxiety is among the most common neighbors. Some people have both, and in that case treating only one leaves half the problem standing. What I refuse is the shortcut, looking at a concentration difficulty and writing down the first name it suggests.
What I ask when the complaint is concentration
Three things change the direction of the conversation. The first is when it started, because ADHD does not appear out of nowhere in adult life, and the childhood and school history has to be there. The second is what happens inside the head at the moment of studying, whether it leaves the page and goes somewhere else, or whether it gets too busy, with worry spinning on top of the reading. The third is what happens when the plan falls apart, because intolerance to changed plans and the need for control point to another territory.
In her case what usually sits underneath showed up too. The fear of letting down the people who bet on her, the need to show she could work and study at the same time, the sense that performance is the currency of recognition. That is not a test result. It is what a person says when the office stays quiet long enough.
The body belongs in the treatment, not in a footnote
When the picture is anxiety, exercise stops being a generic recommendation at the end of the appointment. The meta-analysis led by Brett Gordon and colleagues, at the University of Limerick, in Ireland, gathered in 2017 the randomized trials of resistance training and anxiety, with 16 articles and 922 participants, and found a reduction in symptoms with an effect size of 0.31. The authors themselves open the paper by recalling that aerobic exercise already has a well documented positive effect on anxiety, and that the gap was precisely strength training.
To translate the number, 0.31 is a small to moderate effect, the kind that does not replace treatment in a severe case and adds a great deal when it comes alongside. That is why the conversation about going back to walking and swimming took as much time as the conversation about medication, and not the last five minutes.
Where to start when everything needs to change
She has smoked for years and knows it harms her, and even so the cigarette was not the first item on the list. Nicotine relieves anxiety on the spot, and taking that relief away before the anxiety is being treated tends to bring the attempt down. What a failed attempt leaves behind is not neutral. It leaves the impression that it will not work, and that impression charges a high price next time.
That has been measured. A meta-analysis led by Chad Gwaltney and colleagues, at Brown University, in the United States, gathered in 2009 the 54 studies that followed smokers over time and showed that a person's own confidence in staying off cigarettes predicts the outcome, with a difference of 0.21 standard deviations when measured before the attempt and of 0.47 when measured after quitting. The authors themselves warn that the association is less robust than theory predicted, and even so there it is across 54 studies.
On the order of the changes, the evidence is more modest than intuition. A systematic review coordinated by Erica James, at the University of Newcastle, in Australia, found in 2016 only 6 randomized trials comparing changing everything at once with changing in stages, and concludes that both approaches should be considered equally efficacious. Of the 3 trials that showed any difference, 2 favored the staged approach precisely for smoking. Starting with the easiest target is a clinical bet, and not a proven rule, and the bet rests on the predictor we do have, a winnable victory first, so that the hard change arrives with a different history behind it.
None of this is an argument for not quitting. The meta-analysis led by Gemma Taylor and colleagues, at the University of Birmingham, in the United Kingdom, gathered in 2014 the studies that followed people before and after they stopped smoking, and found less anxiety, less depression and less stress in those who quit, with an effect size of 0.37 for anxiety. Quitting improves anxiety in the medium term, and what gets agreed in the office is when to try.
What changes when the name changes
Swapping the hypothesis is not swapping one word for another on paper. It changes the target of treatment, it changes what improvement to expect and by when, and it changes what a person understands about herself. Leaving the appointment thinking you have an attention defect that has to be compensated with a borrowed tablet is one story. Leaving it understanding that your mind is too full because there is anxiety happening, and that there is treatment for that, is another.
None of this gets settled in one appointment, and it is not meant to. What the first meeting does is build the hypothesis, agree on what will be tried, say what unwanted effects can happen and set when you will speak again. In her case, I agreed to call in a week. That phone call is part of the treatment, not a courtesy.
If you recognized yourself in this scene, the gesture that fits today or tomorrow is small and depends on no diagnosis at all. Next time you sit down to study or to work and cannot, stop for a minute and answer one question, whether your mind left the page or whether it is too full to hold anything else. The answer does not settle a diagnosis, and it is the first thread that whoever evaluates you will need. Pull that thread slowly, because a tangled ball does not come undone by force, and take whatever shows up to an individual evaluation, which is where this conversation really pays off.
Frequently asked questions
How do I tell ADHD from anxiety when both hurt my concentration?
Notice what happens inside your head at the moment of the task. In attention deficit the mind leaves the page and goes to another subject; in anxiety it gets too busy, with worry spinning on top of what you are trying to read. Another sign is the ability to plan: people who can build meticulous plans and suffer when those plans change tend to sit closer to anxiety. This guides the conversation and does not settle a diagnosis, which depends on an individual evaluation.
Can I trust the test of taking a friend's ADHD medication?
It proves nothing. A systematic review on stimulant use as a study aid records that cognitive enhancement is the main reason people give and that it does not occur in healthy adults. What a person usually feels is less sleepiness and more drive, which is not the same as correcting an attention deficit. Using someone else's controlled medication also carries clinical and legal risk. Take the question to an evaluation instead of testing it on your own.
Is it normal to find out about ADHD only in adulthood?
The diagnosis requires a history that comes from childhood, so the picture does not appear from scratch in an adult, even if it only gets a name later. Adult ADHD is common and undertreated: the American national survey led by Ronald Kessler estimated a current prevalence of 4.4% in adults, with high comorbidity and most cases untreated. When the difficulty begins in late adolescence or after, it is worth looking for another explanation first.
Can anxiety be treated with exercise, or is that just advice?
It helps, and there is a measure of it. A meta-analysis of randomized trials with 16 articles and 922 participants found a reduction in anxiety symptoms with resistance training, with an effect size of 0.31, and the authors recall that aerobic exercise already had a well documented positive effect. It is a small to moderate effect, one that does not replace treatment in a severe case and adds a great deal when it comes alongside everything else.
When should I quit smoking if I am treating anxiety?
Quitting smoking improves anxiety, and even so the timing is worth agreeing on. A meta-analysis found less anxiety in people who quit, with an effect size of 0.37, compared with those who kept smoking. What weighs against trying too early is confidence: a meta-analysis of 54 studies showed that believing you will manage predicts the outcome, and a failed attempt hits precisely that. There is no proof that changing in stages beats changing everything at once, so agree on the sequence with whoever is following you.
References
- SHARIF, S.; GUIRGUIS, A.; FERGUS, S.; SCHIFANO, F. The use and impact of cognitive enhancers among university students: a systematic review. Brain Sciences, v. 11, n. 3, 355, 2021. PMID: 33802176.
- MAGNOTTI, S.; BEATTY, A.; BICKFORD, E.; CHANNELL, I.; WEYANDT, L. Prescription stimulant misuse among nursing students: a systematic review. Journal of Addictions Nursing, v. 34, n. 3, p. 216-223, 2023. PMID: 37669341.
- KESSLER, R. C. et al. The prevalence and correlates of adult ADHD in the United States: results from the National Comorbidity Survey Replication. The American Journal of Psychiatry, v. 163, n. 4, p. 716-723, 2006. PMID: 16585449.
- GORDON, B. R.; McDOWELL, C. P.; LYONS, M.; HERRING, M. P. The effects of resistance exercise training on anxiety: a meta-analysis and meta-regression analysis of randomized controlled trials. Sports Medicine, v. 47, n. 12, p. 2521-2532, 2017. PMID: 28819746.
- GWALTNEY, C. J.; METRIK, J.; KAHLER, C. W.; SHIFFMAN, S. Self-efficacy and smoking cessation: a meta-analysis. Psychology of Addictive Behaviors, v. 23, n. 1, p. 56-66, 2009. PMID: 19290690.
- JAMES, E.; FREUND, M.; BOOTH, A.; DUNCAN, M. J.; JOHNSON, N.; SHORT, C. E. et al. Comparative efficacy of simultaneous versus sequential multiple health behavior change interventions among adults: a systematic review of randomised trials. Preventive Medicine, v. 89, p. 211-223, 2016. PMID: 27311332.
- TAYLOR, G.; McNEILL, A.; GIRLING, A.; FARLEY, A.; LINDSON-HAWLEY, N.; AVEYARD, P. Change in mental health after smoking cessation: systematic review and meta-analysis. BMJ, v. 348, g1151, 2014. PMID: 24524926.
Dr. Marcelo Gobbo Jr.
Family and Community Physician (CRM-MG 74.511 · RQE 69038), with a master’s degree in Psychology from the Federal University of Uberlândia and a Laboratory Associate appointment in the Department of Psychiatry at Yale School of Medicine, based at the Program for Recovery and Community Health. He cares for neurodiverse families and people living with severe mental illness, in person and remotely.