How to stop overthinking (and why willpower doesn't work)

You know the feeling. It's 11pm and you're mentally replaying a conversation from three days ago. You're dissecting your own tone of voice. You're constructing the better response you should have given. You're wondering what they thought. You're wondering what you think about what they thought.

Or maybe it's the future version: something is coming up — a difficult conversation, a decision, a presentation — and your brain will not leave it alone. It rehearses every possible outcome. It finds new angles to worry about. It presents evidence for and against, circles back to the beginning, and starts again.

Overthinking — what psychologists call rumination — is exhausting. It feels productive. It isn't.

Don't panic! Here's what's actually happening when you can't turn your thoughts off, why trying harder to stop usually makes it worse, and what actually works.

What overthinking actually is

Rumination is the clinical term for overthinking: the repetitive, passive focus on negative feelings, past events, or future worries, without reaching any resolution. You're not problem-solving — you're looping.

Research by psychologist Susan Nolen-Hoeksema at Yale established rumination as one of the strongest predictors of depression and anxiety disorders. Repeated ruminative thinking creates a feedback loop — thoughts about being depressed or anxious produce more depression and anxiety, which generate more rumination. It impairs creative problem-solving (despite feeling exactly like problem-solving). It predicts social withdrawal. And it keeps the nervous system on alert long after the original trigger has passed.

This is not a character flaw. It is a predictable response to anxiety — and in many ways, to a brain doing exactly what it evolved to do: scan for threats, analyze risks, rehearse difficult scenarios. The problem is that this system was designed for saber-toothed tigers, not inbox anxiety. Yet, it fires without discrimination, and without an off switch.

Why trying not to think about it makes it worse

If I told you right now not to think about a polar bear — specifically, to put all mental effort into not imagining a polar bear — you would immediately picture a polar bear.

This is called the rebound effect, and it's been documented in psychological research since the late 1980s. When people actively try to suppress a thought, that thought becomes more frequent and more intrusive than if they'd simply left it alone.

The same mechanism operates with anxious thoughts, shame, and rumination. Suppression doesn't work. Trying harder to not think about something recruits attention toward it. Willpower isn't the solution here — it's part of why the problem persists.

This is also why advice like "just don't worry about it" lands so badly. It's not just unhelpful — it often makes the loop tighter.

(I couldn't resist.... plus this one is cute...)

What actually helps: changing your relationship to the thought

The shift that makes a real difference isn't trying to eliminate the thought — it's changing your relationship to it.

In Acceptance and Commitment Therapy (ACT), the technique for this is called cognitive defusion. The idea is that our thoughts are not facts — they're mental events, passing through. We're not obligated to take them literally or act on them. And the less we wrestle with them, the less power they hold.

Defusion doesn't make thoughts disappear. It changes what happens when they show up. Instead of the thought being the boss — pulling you into the loop automatically — you get a step of distance. You notice the thought, observe it,

and then decide what you do next.

Practically, defusion might look like:

• Naming what's happening: "I'm having the thought that I'm going to fail." (Not: "I'm going to fail.") The extra layer of language creates distance.

• Labelling the process: "Ah — there's the replay again. There's the worry spiral." Naming the pattern interrupts the fusing with it.

• Imagining the thought as a passing car on a street you're sitting beside — you see it, you notice it, you don't have to get in.

Research shows that defusion techniques produce meaningful reductions in the emotional charge of intrusive thoughts — and that these shifts can happen quickly, even within a single session of practice. Lasting behavioural change builds over weeks of consistent use, but the early experience of relief can be genuinely surprising.

The worry window: giving rumination a container

Another approach that sounds counterintuitive but is well-supported: scheduled worry time.

Rather than fighting intrusive thoughts every time they appear throughout the day, you designate a specific window — say, 15 minutes in the late afternoon — where you are allowed to worry freely. When a ruminative thought comes up outside that window, you acknowledge it and consciously defer it: "I'll think about this at 4:30."

Over time, this does two things. It reduces the all-day bleeding of anxiety into ordinary life. And it reveals something important: when you actually sit down to worry during your designated time, you often find that the urgency has faded, or that the worry loop has less fuel than it did at 11pm.

One note: it helps to schedule your worry window at least two hours before bed. Using it too close to sleep tends to make things harder rather than easier.

Mindfulness: awareness without amplification

You've probably heard mindfulness recommended for anxiety more times than you'd like. Bear with me for a moment, because I want to be specific about what it actually does here — and what it doesn't.

Mindfulness isn't about emptying your mind. It's about developing what researchers call meta-awareness: the ability to notice "I'm ruminating right now" without immediately either suppressing the thought or diving deeper into it. That moment of stepping back — just noticing the loop without fusing with it — is the active ingredient.

Research shows that this kind of meta-awareness reduces both the intensity and duration of ruminative episodes. You're not fighting the thought. You're just... not following it all the way down.

Simple practices that build this skill: a few minutes of focused breathing (not to relax, but to practice noticing when attention wanders and gently bringing it back). A body scan. Even a brief pause to name five things you can physically see. None of this has to be elaborate or spiritual to be effective. But you do have to practice it repeatedly - just like any skill!

Getting into your body and out of your head

Overthinking lives in the verbal, narrative part of the brain. One of the most reliable short-circuits for a thought spiral is doing something that shifts attention into the body: movement, sensation, breath.

This is part of why exercise has such strong evidence for anxiety and low mood — it's not just the neurochemistry [which is also very real and very cool], it's the shift in where attention goes. It's hard to sustain an elaborate worry spiral while you're breathing hard on a trail.

Walk and talk therapy works on this same principle. Moving through a physical environment, attending to sensation, engages a different mode of processing than sitting still with racing thoughts. Many people find that thoughts that felt sticky and overwhelming inside become much more manageable when there's movement underneath them.

When to take the thoughts seriously

Not every ruminative thought is useless noise. Some overthinking is the brain's way of flagging something that actually warrants attention — a relationship that needs a difficult conversation, a situation that needs to change, a decision that deserves more thought.

The distinction worth making: Is this thinking generating new insight, or going in circles? Is it moving toward something, or just replaying? If you've been around the loop ten times and you're in the same place you started, that's rumination. If something new surfaces — some clarity, some direction — that's worth following.

A useful question when you notice you're spiraling: "Is there something actionable here right now?" If yes, write it down and do it. If no, that's the cue to use one of the strategies above rather than continuing to process.

Why this might be worth exploring in therapy

The strategies above are genuinely useful, and many people find meaningful relief from applying them consistently. But chronic overthinking — the kind that's been running for years, that disrupts sleep, strains relationships, and drains daily life of its colour — often has roots worth exploring more carefully.

What are the underlying fears that fuel the loop? What does the rumination help you avoid? What beliefs about control, certainty, or self-worth are feeding it?

ACT, CBT, and Mindfulness-Based Cognitive Therapy (MBCT) all have strong research support for addressing the patterns that maintain rumination. Working with a therapist gives you a place to untangle those roots, not just manage the symptoms.

If overthinking is something you've been struggling with — whether it shows up as constant worry, replay, perfectionism, or an inability to let things go — you don't have to white-knuckle your way through it.

Gwen Preston is a Registered Psychotherapist (Qualifying) offering virtual therapy across Ontario and in-person sessions in Orleans. She specializes in anxiety, burnout, and life transitions, using ACT, CBT, and mindfulness-based approaches tailored to each client. Free 15-minute consultations are available through the booking page.