How Common Is Harm in OCD?
By Justin La Rose, RP, M.Psy · Registered Psychotherapist (CRPO) · Clinical Director, The OCD Clinic
Evidence last reviewed: October 2026
Harm OCD is common: unwanted thoughts or images about hurting yourself or someone else are a recognised OCD theme, and still get missed. In one study, clinicians misidentified OCD with aggressive obsessions 31.5% of the time (Glazier, 2013). The thoughts are ego-dystonic, meaning they clash with your values, which is why they’re so hard to say out loud.
The short answer
- Intrusive thoughts: Unwanted intrusive thoughts are highly prevalent across countries and cultures, with 64% of the sample reporting all four types studied, in a cross-cultural study by Pascual-Vera et al. (2019).
- Obsessions and compulsions: More than a quarter of US adults reported obsessions or compulsions at some point in life, while 2.3% met criteria for OCD, in a national survey by Ruscio et al. (2010).
- Often missed: Mental health professionals misidentified OCD with aggressive obsessions 31.5% of the time in a study by Glazier et al. (2013).
- In my practice: Many people I see have never said the thought out loud to anyone.
Why are harm thoughts so hard to say out loud?
Because OCD goes after what you care about. If you love your kids, it hands you a thought about hurting them. New parents get this one often, which is why we wrote about intrusive thoughts about harming your baby. The horror is the ego-dystonic part, and shame keeps it hidden. More on that in why shame keeps OCD hidden. Much of it is invisible, with rituals happening in your head, the pattern often called Pure O.
What do the rituals teach you?
They teach you the thought was dangerous. It’s like my keys: I held them like a weapon for years after a dog attack, nothing happened, and the keys got the credit. Harm rituals work the same way:
| What people do | What the brain learns |
|---|---|
| Hide the knives | The knives were the problem |
| Ask someone if you’re a good person | The question needed an answer |
| Replay the day to check you did nothing | Your memory can’t be trusted. Repeated checking lowers confidence in memory, not its accuracy (Abbasi Jondani, 2023) |
That loop is what Exposure and Response Prevention (ERP) works on. Clinicians can find more in the harm OCD risk assessment guide.
Frequently asked questions
Are harm thoughts the most common OCD theme?
I can’t give you a reliable ranking from the research I’ve verified. The studies do show that intrusive thoughts are common across cultures and that aggressive obsessions get missed. In my practice, harm is one of the themes people hide the longest.
Does having harm thoughts mean I’m dangerous?
A thought on its own can’t answer that, and neither can a web page. Having a thought isn’t the same as intending to act. A clinician assesses risk from the whole picture, not from one symptom, and that’s what a proper assessment is for.
Is harm OCD treated differently from other OCD?
The content is different, but the method is the same. ERP, the OCD treatment with the largest body of trial evidence (Öst, 2015), works the same way here: you face the thought and drop the rituals, so you learn you can carry the uncertainty without them.
What should you read next?
If this sounds familiar, the next step is a proper assessment, not more searching. OCD is the focus of this clinic, and we treat it with exposure and response prevention (ERP).
If you ever feel you might act on a thought to hurt yourself or someone else, get help now. In Canada, call or text 9-8-8 (Suicide Crisis Helpline), call 911, or go to the nearest emergency department.
Book a Free ConsultationHow we researched this page
This page draws on a study of clinicians missing OCD (Glazier et al., 2013), a US national survey (Ruscio et al., 2010), a cross-cultural study of intrusive thoughts (Pascual-Vera et al., 2019), checking research (Abbasi Jondani et al., 2023) and a meta-analysis of ERP trials (Öst et al., 2015), alongside what I see in my own practice. None of these studies measured how many people with OCD have harm obsessions specifically, so this page gives no figure for that, and the survey covers US adults only.
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). How Common Is Harm in OCD?. The OCD Clinic. https://theocdclinic.ca/ocd-faq/how-common-is-harm-in-ocd