Why Can't I Stop Overthinking? The Filing Cabinet Your Nervous System Keeps Opening

It's late. You've replayed the conversation four times. You've drafted the email in your head, in three different tones, and sent none of them. You've solved a problem that hasn't happened yet, then solved it again, slightly differently.

It feels productive. It feels like you're handling something.

Usually, you're not. That isn't because you're bad at thinking. It's because you may be trying to think your way out of something that isn't really a thinking problem.

Why overthinking feels like problem-solving

When stress hormones like adrenaline and cortisol rise, the body gets ready for action. Your heart rate climbs, your attention narrows, and you start scanning for what's wrong. In that state, the mind has one job: find the problem and fix it.

That's useful when there's an actual problem to fix, like a deadline, a leaky roof, or a car drifting into your lane.

The trouble starts when there's nothing concrete to act on. The mind keeps going anyway. Researchers distinguish problem-solving, which tends to end in a decision or an action, from repetitive negative thinking, such as worry and rumination, which tends to loop.

There's also a sneaky reason the loop sticks. Psychologist Thomas Borkovec and colleagues found that worry is mostly verbal, and thinking in words may briefly dampen the body's alarm. That small hit of relief rewards the habit. The mind learns that worrying "helps," even though the underlying stress never actually gets resolved.

Overthinking, in other words, is very convincing cosplay of problem-solving.

The narrator strikes again

In our post on one nervous system, we described the thinking part of the brain as less of a pilot and more of a narrator. Split-brain research by Michael Gazzaniga showed that one part of the brain, which he called the interpreter, readily invents confident explanations for what we feel and do, whether or not it knows the real reasons.

Overthinking is that narrator working overtime.

The filing cabinet

Picture the narrator working at a desk in front of a big filing cabinet.

When stress hormones rise, a message lands on the desk: Something is wrong. The narrator's job is to explain it. So it pulls open a drawer and grabs a file.

Work. That thing you said at dinner. Money. Your health. The odd look from your neighbour.

The file it grabs doesn't have to be the cause. It just has to fit. Once a file is on the desk, the narrator builds a case: reasons, evidence, worst-case scenarios, and a few appendices. Now the stress feels like it's about that file.

If your nervous system tends to run anxious, those messages arrive often. The drawer gets opened often. And the same thick, well-worn files near the front get pulled again and again.

There's research behind the general idea. Classic studies, including Schachter and Singer's work in the 1960s and a well-known experiment on a wobbly suspension bridge, suggested that people use their surroundings to make sense of physical arousal, and sometimes get the label wrong. Those early studies have real limitations, and not all of their findings have replicated cleanly. But the broader point holds up well: the body sends the signal, and the mind supplies the story.

Sometimes the file is the right one. You may genuinely have a lot going on. The point isn't that your worries are imaginary. It's that the feeling of alarm isn't proof that the file on the desk is the cause.

Allostatic load: when the body is running a tab

Neuroscientist Bruce McEwen used the term allostasis for the way the body adapts to demands, and allostatic load for the wear and tear that builds up when stress responses switch on too often or don't switch off.

Think of it as a tab the body keeps running. Short sleep, caregiving, chronic pain, financial pressure, discrimination, and long stretches without rest all add to it. A body carrying a high tab tends to send something is wrong messages more often, and with less provocation.

The narrator can't see the tab. It only sees the message. So it heads to the filing cabinet.

This is why overthinking often isn't purely a mental problem. It can be the mind's best guess at explaining a physical state. If stress for you shows up more in the body than as worry, our post on why stress and anxiety don't always feel like anxiety goes deeper.

Why you can't think your way out

Trying to stop overthinking by thinking harder is a bit like asking the narrator to close the cabinet by reading more files. The more you analyze, the more files end up on the desk.

Telling yourself to just stop thinking about it doesn't work well either. In a classic study by Daniel Wegner, people asked not to think about a white bear thought about it more. Trying to push a thought away tends to keep it close.

If the alarm is coming partly from the body, the body needs to be part of the answer.

How to stop overthinking: what tends to help

These are general ideas, not individual advice. You're the best judge of what feels settling for you. Notice what fits, and skip anything that feels uncomfortable. That's useful information too.

If your narrator tends to be harsh as well as busy, you might find our post on the inner critic helpful.

How therapy can help with overthinking

In therapy, our clinicians tend to work from both directions. Top-down, that can mean understanding which files keep getting pulled and why, and learning to respond to them differently. Approaches like cognitive behavioural therapy have research support for worry and rumination. Bottom-up, it can mean building the body's capacity to settle, so the alarm fires less often to begin with. That's the heart of nervous-system-informed therapy. Mindfulness sits between the two, helping you notice racing thoughts without getting pulled along by them. If you'd like to build a practice outside therapy, Vistas also offers mindfulness and meditation coaching as its own service, separate from psychotherapy.

It may be worth reaching out if overthinking is affecting your sleep, work, or relationships, or if it comes with panic, low mood, or feeling stuck. Your family doctor can also help rule out physical factors that might be adding to the load.

Vistas offers anxiety therapy in person in Toronto and Ottawa, and virtually across Ontario.

Common questions

Why can't I stop overthinking? Overthinking often starts as the mind's attempt to explain and fix a feeling of stress. When there's nothing concrete to act on, the effort loops. Because worry can briefly take the edge off the body's alarm, the habit gets reinforced, even though the underlying stress stays.

Is overthinking a sign of anxiety? It can be part of anxiety, but it also shows up with ordinary stress, low mood, and big life changes. A regulated health professional can help you understand what's going on for you.

Why is overthinking worse at night? At night there are fewer distractions, and tiredness lowers our capacity to steady ourselves. With less competing for attention, the filing cabinet tends to get louder. If racing thoughts often keep you up, therapy for insomnia may help.

Can therapy help with overthinking? Many people find it helpful. Approaches like CBT have research support for worry and rumination, and body-aware work can help lower the stress signals that set the loop in motion.

Where can I get help with overthinking in Ontario? Vistas offers anxiety therapy in person in Toronto and Ottawa, and virtually anywhere in Ontario. You're welcome to start with a free consultation.

The filing cabinet isn't going anywhere. But it doesn't have to run the office.

Further Reading & Sources

If you'd like to learn more about overthinking, worry, and the body, these resources offer additional depth:

• Borkovec, T. D., Alcaine, O. M., & Behar, E. (2004). Avoidance theory of worry and generalized anxiety disorder. In R. G. Heimberg, C. L. Turk, & D. S. Mennin (Eds.), Generalized anxiety disorder: Advances in research and practice (pp. 77–108). Guilford Press. Why worry can feel helpful in the moment and still keep stress going.
• Borkovec, T. D., Wilkinson, L., Folensbee, R., & Lerman, C. (1983). Stimulus control applications to the treatment of worry. Behaviour Research and Therapy, 21(3), 247–251. https://doi.org/10.1016/0005-7967(83)90206-1. The early research on scheduled worry time.
• Watkins, E. R. (2008). Constructive and unconstructive repetitive thought. Psychological Bulletin, 134(2), 163–206. https://doi.org/10.1037/0033-2909.134.2.163. How helpful and unhelpful forms of repetitive thinking differ.
• Querstret, D., & Cropley, M. (2013). Assessing treatments used to reduce rumination and/or worry: A systematic review. Clinical Psychology Review, 33(8), 996–1009. https://doi.org/10.1016/j.cpr.2013.08.004. A review of mindfulness-based and cognitive behavioural approaches to worry and rumination.
• McEwen, B. S. (1998). Protective and damaging effects of stress mediators. New England Journal of Medicine, 338(3), 171–179. https://doi.org/10.1056/NEJM199801153380307. The foundational paper on allostasis and allostatic load.
• Schachter, S., & Singer, J. (1962). Cognitive, social, and physiological determinants of emotional state. Psychological Review, 69(5), 379–399. https://doi.org/10.1037/h0046234. A classic, and debated, study on how we label physical arousal.
• Dutton, D. G., & Aron, A. P. (1974). Some evidence for heightened sexual attraction under conditions of high anxiety. Journal of Personality and Social Psychology, 30(4), 510–517. https://doi.org/10.1037/h0037031. The suspension bridge study on misreading arousal.
• Wegner, D. M., Schneider, D. J., Carter, S. R., & White, T. L. (1987). Paradoxical effects of thought suppression. Journal of Personality and Social Psychology, 53(1), 5–13. https://doi.org/10.1037/0022-3514.53.1.5. The "white bear" study.
• Gazzaniga, M. S. (2011). Who's in charge? Free will and the science of the brain. Ecco. An accessible account of the brain's interpreter.

This post offers general information for educational purposes. It is not therapy, does not replace individualized mental-health care, and does not establish a therapeutic relationship. If you're experiencing distress or need support, please connect with a qualified mental-health professional in your area. If you are in immediate distress or at risk of harm, in Canada you can call or text 9-8-8 (Suicide Crisis Helpline) or call 9-1-1, and internationally you can visit FindAHelpline.com to locate free, confidential support services available in your specific country and language.