Checking OCD
The More You
Check, The Less
Sure You Get.
By Justin La Rose, RP, M.Psy · Registered Psychotherapist (CRPO) · Clinical Director, The OCD Clinic
Evidence last reviewed: October 2026
Checking OCD is a type of OCD where doubt drives you to check things over and over: locks, the stove, appliances, sent emails, your body, your own memory. Each check is a bid for certainty. Did I lock it? Did I turn it off? Did I do something wrong? The relief never lasts, so the checking never stops, and the doubt gets louder with every round.
Here's the thing. Checking makes you less sure, not more. Every repeated check creates a new, near-identical memory that blurs with the last one. Your memory accuracy holds up, but your confidence in that memory erodes. The compulsion that's supposed to end the doubt is the thing manufacturing it.
Exposure and Response Prevention (ERP) is the OCD treatment with the largest body of trial evidence (Öst, 2015). For checking, the exposure is deceptively simple: lock the door once, turn off the stove once, send the email, and walk away on purpose. Response prevention means no going back, no replaying it in your head, no photo, no asking someone if it's fine. It's like the gym. If the front door is your 300-pound lift, we start lighter, maybe the sent email. You leave the doubt unanswered and learn you can carry it through your day. The fix was never a better check. It was fewer of them.
The short answer
- Checking and memory: A meta-analysis of checking experiments found repeated checking lowers confidence in memory, with little or no effect on how accurate the memory is (Abbasi Jondani et al., 2023).
- First-line treatment: Exposure and Response Prevention (ERP), a form of CBT, is a first-line treatment for OCD in the American Psychiatric Association's practice guideline (Koran et al., 2007).
- Strength of the evidence: Across 37 randomized trials, CBT that includes ERP produced large effects for OCD compared with waitlist and placebo conditions (Öst et al., 2015).
- How exposure works: Exposure works through expectancy violation: you leave the stove unchecked and learn whether the fire you predicted arrives, and whether you can carry the doubt (Craske et al., 2014).
What does checking OCD look like?
Checking OCD looks like going back, again and again, to confirm something you already did, and it usually takes one of four forms. It overlaps with harm OCD when the fear is that you hurt someone, with health anxiety OCD when the thing you check is your body, and with sexual orientation OCD when you scan yourself for a reaction to prove what you are.
Physical Checking (Locks, Appliances, Safety)
Going back to the door to confirm it's locked. Returning to the stove, the iron, the taps. Driving back to make sure the car is locked or that you didn't hit something. The check feels like it should end the doubt, but the relief lasts minutes before the next wave arrives.
Responsibility and Harm-Prevention Checking
Checking driven by the fear that a small lapse on your part could cause a catastrophe: a fire, a flood, a break-in, an accident. It runs on an inflated sense of responsibility. Being certain starts to feel like the only thing standing between your family and disaster.
Memory Checking ("Did I Do It?")
Mentally replaying the past to confirm what you did or didn't do. Re-running the moment you left the house, scanning your memory for proof. The more you review, the foggier the memory gets, and the foggier it gets, the more you feel you have to check.
Reassurance and Online Checking
Asking other people whether everything is okay. Googling symptoms, scenarios, or worst-case outcomes. Re-reading sent emails and texts for mistakes. Checking your body for signs of illness. The internet and the people around you become tools the compulsion uses to chase certainty.
What are the common checking OCD compulsions?
The common ones are going back to locks and appliances, re-reading messages, replaying events in your head and asking other people to confirm, and each one buys a few seconds of certainty. Then the doubt comes back with a sharper question, and the next check has to be more thorough than the last.
- Returning to check locks, the stove, the oven, or appliances, often multiple times
- Driving back to confirm the car is locked or that you didn't hit anyone
- Re-reading sent emails and texts to make sure you didn't make a mistake
- Mentally replaying events to confirm "did I do it?" or "did I say that?"
- Checking your body for signs of illness, lumps, or symptoms
- Googling worst-case scenarios or repeatedly searching for reassurance online
- Asking family or friends to confirm that everything is okay
- Counting, retracing steps, or photographing things to "prove" you checked
Why does checking make the doubt worse?
Checking makes the doubt worse because repeated checking lowers confidence in memory, with little or no effect on memory accuracy (Abbasi Jondani, 2023). Most people assume they check because their memory is unreliable. The research points the other way, and this is the memory paradox at the heart of checking OCD.
- Each repeated check creates a new, near-identical memory that blurs with the last one
- Your brain shifts from vivid "I saw the lock click" to vague "I know I probably did it"
- That shift lowers your confidence in the memory, even though the memory itself is accurate
- Lower confidence feels like more doubt, which triggers another check
- The doubt spreads to attention and perception, not just memory ("was I even paying attention?")
- The problem was never your memory. It's your trust in it, and checking erodes that trust further
Some people try to put the check off instead of dropping it. Waiting a set time and then checking anyway keeps the deal alive, which is why the 15-minute rule isn't the same as response prevention. When most of the checking happens in your head, the patterns on the Pure O page will look familiar.
Related Resources
FAQ
What Else Do People Ask About It?
Because checking is what feeds the doubt. Every repeat creates a new, near-identical memory that blurs with the last one, so vivid 'I saw the lock click' blurs into vague 'I think I did it.' Your memory itself holds up, but your confidence in it drops with each check. The thing you're doing to feel sure is the thing manufacturing the uncertainty.
Because checking OCD is a trust problem more than a memory problem. Research on repeated checking finds it has little or no effect on how accurate your memory is (Abbasi Jondani, 2023). What erodes is confidence in the memory, because repeated checking trains your brain to distrust what it already knows. That's why 'just remembering harder' never works.
Careful is checking the stove once and moving on. OCD is checking it, walking away, doubting, and going back again, with the relief never lasting. Look at whether the checking is driven by dread, eats real time, and repeats past the point of reason. If certainty keeps slipping the moment you turn away, that pattern is worth a proper assessment.
With Exposure and Response Prevention (ERP), the OCD treatment with the largest body of trial evidence (Öst, 2015). You lock the door once, walk away, and deliberately don't go back. You carry the unanswered doubt into your day and learn that you can. People who have checked for years do this work too. You can start with a free 20-minute consultation.
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Book Free ConsultationHow we researched this page
This page draws on a meta-analysis of experimental studies on repeated checking and memory (Abbasi Jondani et al., 2023), the American Psychiatric Association's practice guideline for OCD (Koran et al., 2007), a meta-analysis of 37 randomized trials of CBT and ERP (Öst et al., 2015) and research on inhibitory learning in exposure therapy (Craske et al., 2014), alongside what I see in my own practice. The checking studies are experiments, mostly with people who don't have an OCD diagnosis, and their authors note the results may generalize less well to people with OCD, so they show the mechanism rather than measure checking OCD in daily life. The treatment trials mix OCD subtypes rather than studying checking alone.
A note on my perspective
I run a private clinic that treats OCD with ERP, and I'm paid when people book with us. Read what I write with that in mind. Public and lower-cost routes exist too, and the Ontario OCD treatment guide lays them out next to ours.
About the author
Justin La Rose, RP, M.Psy is a Registered Psychotherapist with the College of Registered Psychotherapists of Ontario (CRPO) and Clinical Director of The OCD Clinic in Toronto. He has worked in mental health for more than 25 years and treats OCD with Exposure and Response Prevention (ERP). You can confirm his registration on the CRPO public register.
Client stories on this site are composites, with names and identifying details changed. How we write client stories
How to cite this page
La Rose, J. (2026). Checking OCD: The More You Check, the Less Sure You Get.. The OCD Clinic. https://theocdclinic.ca/checking-ocd