ADHD, Anxiety and Overthinking: Telling the Different Kinds of Busy Mind Apart
It's 11pm and you're lying awake. Your mind jumps from a conversation earlier, to a bill you haven't paid, to whether a friend is annoyed with you, to an idea for a project, and back to the bill. Someone tells you to "stop overthinking", which makes it sound like one simple habit. It rarely feels that simple.
"Overthinking" can describe several different experiences, and they don't all respond to the same approach. This article helps you tell them apart.
In short: with ADHD, a busy mind may involve wandering thoughts, worry about the future, rumination about the past or yourself, or a genuine backlog of unfinished tasks. Research suggests these are linked with ADHD and with anxiety and low mood, but it can't show that ADHD causes overthinking. Naming which kind is happening can help you choose a more useful response.
Four kinds of busy mind
Mind-wandering is attention drifting from what you're doing to unrelated thoughts. Many adults with ADHD describe it as constant mental activity that jumps between topics. A 2018 review describes this kind of excessive, spontaneous mind-wandering as something people with ADHD characteristically report.
Worry is thinking about what might go wrong in the future. It often takes the form of "what if…?" questions, and it can feel productive even when it isn't leading anywhere.
Rumination is going over the past or over yourself, often asking "why?": why did I say that, why am I like this? It tends to deepen low mood rather than solve anything.
Unfinished practical demands are real tasks, such as a form, a reply or an appointment, that keep popping into your head because they haven't been dealt with or written down. These aren't a thinking problem as such. Your mind is reminding you of something that genuinely needs doing.
On any given evening, all four can blur together. Separating them is the first step.
What research suggests, and what it doesn't
ADHD in adults commonly occurs alongside other difficulties. A large US survey found that adult ADHD often occurs alongside many other mental health conditions.
Several studies have looked at the role of thinking patterns. In a study of 159 adults with ADHD, ADHD symptoms were linked with anxiety and depression through higher levels of excessive mind-wandering and rumination. A 2026 general-population study found a similar pattern with racing thoughts.
These findings are useful but limited. Both studies measured everything at one point in time, so they can't show which came first or what causes what. Another large study of university students found that the link between ADHD symptoms and mind-wandering or rumination became weaker once other factors, including symptoms of anxiety and low mood, were taken into account. So the relationship is real but complicated, and not everyone with ADHD struggles with overthinking.
A cycle that can keep it going
This is an illustrative cycle and a fictional example, not a universal explanation.
Dan is 26. At 11pm he remembers an email he meant to send.
1. Trigger: the unsent email comes to mind.
2. Thought: "I've let everyone down again. They must think I'm useless."
3. Thinking pattern: worry ("What if I get in trouble?") mixes with rumination ("Why can I never just do things?").
4. Response: he stays up checking his phone, trying to settle the worry, then drafts and redrafts the email in his head.
5. Immediate effect: brief relief whenever he reassures himself, but no actual decision.
6. Longer-term consequence: he sleeps badly, finds it harder to concentrate the next day, misses something else, and "I always let people down" feels more convincing.
Notice that one part of this, the unsent email, is a practical demand. Another part, "I'm useless", is a self-critical belief. They need different responses.
Ways to respond to each kind
These are general ideas for reflection, not a treatment plan. Different approaches suit different people.
1. Name what's happening. Pausing to ask "Is this wandering, worry, rumination or a real task?" can create a little distance. It works best as a gentle label rather than a judgement. If you can't tell, that's fine; the question itself often slows things down.
2. Get practical demands out of your head. If it's a real task, write it somewhere you trust, with a note of when you'll deal with it. The aim is to reassure your mind that it won't be lost, not to solve it at 11pm. Keep the method simple; a notepad by the bed may work better than a complicated system.
3. Ask whether a worry is solvable now. If there's a clear next step you can take, take it or schedule it. If the worry is about something you can't influence tonight, notice that continuing to think about it is unlikely to produce an answer. This distinction is commonly used in CBT for anxiety.
4. Shift rumination from "why" to "what next". "Why am I like this?" rarely has a satisfying answer. "What's one thing that would help tomorrow?" is more likely to lead somewhere. If the question feels impossible, it may be a sign that the thoughts are being driven by tiredness or low mood.
5. Be cautious about pushing thoughts away. Trying hard not to think something often makes it more noticeable. Letting thoughts pass in the background while you return to something absorbing, such as a podcast or a simple activity, may suit some people better.
When to seek support
It may be worth getting support if worry or rumination is affecting your sleep, work or relationships most days, or if your thoughts are increasingly harsh towards yourself. For persistent worry, NICE recommends CBT as one evidence-based option for generalised anxiety disorder in adults.
In therapy, the work might involve building a shared picture of your own cycle, separating practical difficulties from anxious and self-critical thinking, and trying out responses that fit how your attention works. Therapy for ADHD-related distress, including a busy mind and feeling less in control, is something I offer. You're welcome whether or not you have a diagnosis.
Frequently asked questions
Is overthinking a symptom of ADHD?
It isn't one of the formal diagnostic criteria, and plenty of people without ADHD overthink. Many adults with ADHD do describe a busy or restless mind, and research suggests links with anxiety and rumination, but the experience varies a lot.
Would ADHD medication stop my overthinking?
Medication questions are best discussed with your prescriber or ADHD service. Therapy can help with the patterns of thinking and coping, whether or not you take medication.
Thinking about next steps
If a busy mind is wearing you down and you'd like to explore what might help, you're welcome to book a free 20-minute consultation by phone or video. We can talk about what you're experiencing and whether therapy feels like a good fit.
Sources and further reading
• Bozhilova, N. S., Michelini, G., Kuntsi, J., & Asherson, P. (2018). Mind wandering perspective on attention-deficit/hyperactivity disorder. Neuroscience & Biobehavioral Reviews, 92, 464–476. https://doi.org/10.1016/j.neubiorev.2018.07.010
• Kandeğer, A., Odabaş Ünal, Ş., Ergün, M. T., & Yavuz Ataşlar, E. (2024). Excessive mind wandering, rumination, and mindfulness mediate the relationship between ADHD symptoms and anxiety and depression in adults with ADHD. Clinical Psychology & Psychotherapy, 31(1). https://doi.org/10.1002/cpp.2940
• Fredrick, J. W., et al. (2020). Sluggish cognitive tempo and ADHD symptoms in relation to task-unrelated thought: examining unique links with mind-wandering and rumination. Journal of Psychiatric Research, 123, 95–101. https://doi.org/10.1016/j.jpsychires.2020.01.016
• Kessler, R. C., et al. (2006). The prevalence and correlates of adult ADHD in the United States: results from the National Comorbidity Survey Replication. American Journal of Psychiatry, 163(4), 716–723. https://doi.org/10.1176/ajp.2006.163.4.716
• NICE (2011, updated 2020). Generalised anxiety disorder and panic disorder in adults: management (CG113). https://www.nice.org.uk/guidance/cg113/chapter/Recommendations
• Devenish, B., Weiner, L., & Papadopoulos, N. (2026). The role of rumination and racing thoughts in co-occurrence of ADHD symptoms, depression and anxiety symptoms. Australian Journal of Psychology, 78(1), 2679669. https://doi.org/10.1080/00049530.2026.2679669