For adults, young people and parents
Exposure and response prevention (ERP)
ERP is the psychological treatment NICE recommends for OCD (CG31) and the one with the most trial evidence (Öst and colleagues, 2015). This page sets out what it is, what happens in a session and what it needs in order to work.
Interactive
How treatment works
Four short steps: why anxiety and OCD keep going, what one practice looks like, what changes with repetition, and what the research says is happening in the brain. Choose the example closest to yours.
Why it keeps going
A compulsion is anything you do to make the anxiety or the doubt go away, such as washing, checking, or asking someone to reassure you. It brings relief, usually within seconds, and anything that brings relief that quickly becomes more likely to happen again next time. The relief also teaches something that is not true, that the danger was real and you only avoided it because you acted. Because the compulsion ends the situation early, you never get the chance to learn that you could have handled the anxiety and the doubt without it.
- 1
- 2Without the compulsion, the anxiety rises higher and stays up for a while. This is expected, and you know it is coming because we plan each step together beforehand.
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- 4
One practice, up close
Exposure means meeting the thing that sets off the OCD on purpose, in small steps that you choose and agree with me beforehand, and then not doing the compulsion. You start with a step that feels manageable rather than the one you fear most, and the first practices can happen in the session with me there. Without the compulsion to bring it down, the anxiety usually rises higher than it would have and stays up for a while. This is planned for, and it gets easier each time you know what is coming.
Anxiety often comes down on its own, but it does not have to for the practice to count. What you are learning is that you can handle the anxiety, and not knowing for certain, without doing the compulsion. Sometimes you also see that the feared thing did not happen, which helps, but with OCD the fear is often about something that cannot be checked, such as whether you are a bad person or whether something will go wrong years from now. That is why the aim is to get better at carrying the doubt rather than to prove it wrong. Doing the compulsion would have brought the anxiety down sooner, but you would not have found out that you can manage without it. The green line is the same trigger after repeated practice: the anxiety rises a little and passes on its own, without an urge that needs answering.
- Your ability to tolerate anxiety
- Your overall anxiety, day to day
- How high the anxiety went during that practice
What repetition changes
Across practices the anxiety still rises each time, though it tends to peak lower and settle more easily. The most important changes are in the two lines: your ability to handle the anxiety and discomfort without needing to fix it, and your overall anxiety from day to day. Real progress is less smooth than this, and a harder week is normal rather than a setback.
Research suggests that exposure does not delete the old fear but rather builds new learning that competes with it. That is why practice is varied, across different places, times and versions of the trigger, so the new learning holds, and why an old fear can flare after stress or a long gap without meaning treatment has failed.
What is happening in the brain
Brain-imaging studies find differences in OCD in circuits that link the front of the brain, the orbitofrontal and cingulate cortex, with deeper structures, the striatum and thalamus. These are associations: they show the circuits behave differently, not that they cause OCD on their own.
Research on how fears are unlearned, much of it in animals and supported by human imaging, suggests the ventromedial prefrontal cortex (vmPFC) helps to calm the amygdala’s alarm response, with the hippocampus tying that new learning to the situations it happened in. The alarm is not removed; the new learning sits alongside it. When people improve with CBT and ERP, activity in the OCD circuits tends to shift towards more typical levels, as it also does with medication. The effects are modest and many studies are small, so this shows how learning fits with the brain rather than proving that treatment rewires it.
Step 1 of 4
An illustration, not a measurement and not a diagnosis. Real courses vary from person to person, and exposure is planned and paced with a clinician. NICE recommends CBT that includes ERP for OCD (guideline CG31, currently being updated). In research studies, around half to two thirds of people who complete ERP respond, fewer recover fully, and many still have some symptoms (Öst and colleagues, 2015).
Sources
- Salkovskis, P. M. (1985). Obsessional-compulsive problems: a cognitive-behavioural analysis. Behaviour Research and Therapy, 23(5), 571-583. doi
- Craske, M. G., Kircanski, K., Zelikowsky, M., Mystkowski, J., Chowdhury, N., & Baker, A. (2008). Optimizing inhibitory learning during exposure therapy. Behaviour Research and Therapy, 46(1), 5-27. doi
- Craske, M. G., Treanor, M., Conway, C. C., Zbozinek, T., & Vervliet, B. (2014). Maximizing exposure therapy: an inhibitory learning approach. Behaviour Research and Therapy, 58, 10-23. doi
- Craske, M. G., Treanor, M., Zbozinek, T. D., & Vervliet, B. (2022). Optimizing exposure therapy with an inhibitory retrieval approach and the OptEx Nexus. Behaviour Research and Therapy, 152, 104069. doi
- Bouton, M. E. (2004). Context and behavioral processes in extinction. Learning & Memory, 11(5), 485-494. doi
- Milad, M. R., & Quirk, G. J. (2012). Fear extinction as a model for translational neuroscience: ten years of progress. Annual Review of Psychology, 63, 129-151. doi
- Stein, D. J., et al. (2019). Obsessive-compulsive disorder. Nature Reviews Disease Primers, 5, 52. doi
- van der Straten, A. L., Denys, D., & van Wingen, G. A. (2017). Impact of treatment on resting cerebral blood flow and metabolism in obsessive compulsive disorder: a meta-analysis. Scientific Reports, 7, 17464. doi
- Öst, L.-G., Havnen, A., Hansen, B., & Kvale, G. (2015). Cognitive behavioral treatments of obsessive-compulsive disorder: a systematic review and meta-analysis. Clinical Psychology Review, 40, 156-169. doi
What ERP is
ERP is a behavioural treatment with two parts, and both are needed. Exposure means deliberately approaching the thoughts, situations, objects and body sensations that set off your anxiety, one planned step at a time. Response prevention means not doing what you would normally do to make the anxiety or doubt go away, such as washing, checking, asking for reassurance, going back over things in your head or avoiding. Those compulsions keep OCD going because each one brings relief within seconds, and the relief teaches your brain that the danger was real and the ritual dealt with it. The thought then comes back more strongly and the ritual takes longer.
Where cognitive work fits, and why discussing the thoughts is not enough
ERP is the part of CBT that NICE recommends as a first-line treatment for OCD and for body dysmorphic disorder. Going over the evidence for an obsession again and again helps less, because in a session it works as reassurance, which is the response the treatment is trying to interrupt. If previous therapy for your OCD was mainly discussion and did not include planned exposure with the compulsions dropped, ERP will be a different piece of work.
The exposure list
Early on we write a list, sometimes called a hierarchy, of the situations you avoid or carry out rituals around, each rated out of 100 for difficulty. It needs to reach the real fear at the top, because stopping short tends to leave the problem in place. The ratings help us choose a manageable place to start, and once you are under way we mix easier and harder items, because varied practice may help the learning last.
A worked exposure list, step by step
This is a made-up example for an adult who fears passing illness to their family.
- Touch the inside handle of my own front door, no washing for thirty minutes (25)
- Touch a supermarket trolley handle, then eat a sandwich without washing first (40)
- Use a public toilet, wash once for twenty seconds only, no second wash (70)
- Do all of the above and then make my daughter’s packed lunch (90)
The last item is the situation you fear most. The easier items are steps towards it.
What happens in a session
Sessions follow the same order each week, and nothing happens that we have not agreed out loud beforehand. Each exposure is planned to be a stretch but manageable, and it becomes easier with repetition.
What happens in an ERP session, in order
- We review the week, including what you practised and what you avoided.
- We agree today’s exposure from the list.
- We agree which compulsions you will not do, including the ones done in your head.
- We name what the OCD is telling you and how much anxiety and doubt you expect to manage.
- You do the exposure. With children I can go first, or do it alongside them.
- We stay with it long enough to learn something, then repeat it in a different place or way.
- You put what you learned into your own words, usually about how you handled the anxiety and the doubt.
- We write down the practice for the coming week.
Dropping the compulsions
Not doing the compulsion during and after an exposure matters as much as the exposure itself. That includes asking a partner or parent for reassurance, searching online, going back over events in your head and checking inside yourself for whether the anxiety has gone. The compulsions done silently in your head are the easiest to miss, because nobody else can see them, and helping you spot them is a large part of my job.
Why we do not wait for the anxiety to fall
Older versions of ERP asked people to stay in an exposure until their anxiety had halved. The current understanding is that exposure builds new learning alongside the old fear rather than deleting it. With OCD the most useful learning is usually that you can handle the anxiety and the uncertainty without doing the compulsion. Sometimes you also see that the feared thing did not happen, but many OCD fears cannot be checked either way, so the aim is not to prove the doubt wrong. For that reason we vary where and how you practise, drop the small things you do to feel safer, such as keeping sanitiser in a pocket, and sometimes end an exposure while the anxiety is still high. An exposure can count as a success even if your anxiety stayed high throughout.
Practice between sessions
Most of the change happens between sessions, so practice is agreed and written down, saying which exposure, how often and for how long. ERP can stall when exposures are done once and never repeated, when there is no practice between weekly sessions, or when family members keep giving reassurance. If practice has not happened two weeks running, we look again at the step. An exposure planner and a practice log are on the worksheets page.
Children and teenagers
With a younger child the OCD is given a name, so that it becomes something outside the child to stand up to, and parents are closely involved. Reducing family accommodation, meaning the ways family members join in with rituals or give reassurance to ease the child’s distress, is an important part of treatment for child OCD, because accommodation is linked with more severe symptoms (Peris and colleagues, 2008). With a teenager, the young person holds the plan and parents step back. Where a young person will not attend, the work can go through the parents instead, using a different treatment, SPACE, in which the child does not attend and the parents change how they respond.
Draw your own pattern
The OCD loop tool lets you type in the trigger, the doubt, the feeling and what you do to make it stop, and draws them as a circle showing how each one leads back to the start. Nothing you type is stored or sent anywhere.
Sources
- Öst, L.-G., Havnen, A., Hansen, B., & Kvale, G. (2015). Cognitive behavioral treatments of obsessive-compulsive disorder: A systematic review and meta-analysis of studies published 1993-2014. Clinical Psychology Review, 40, 156-169. doi.org/10.1016/j.cpr.2015.06.003 (opens in a new tab)
- Peris, T. S., Bergman, R. L., Langley, A., Chang, S., McCracken, J. T., & Piacentini, J. (2008). Correlates of accommodation of pediatric obsessive-compulsive disorder: Parent, child, and family characteristics. Journal of the American Academy of Child and Adolescent Psychiatry, 47(10), 1173-1181. doi.org/10.1097/CHI.0b013e3181825a91 (opens in a new tab)
- Pediatric OCD Treatment Study (POTS) Team. (2004). Cognitive-behavior therapy, sertraline, and their combination for children and adolescents with obsessive-compulsive disorder: The Pediatric OCD Treatment Study (POTS) randomized controlled trial. JAMA, 292(16), 1969-1976. doi.org (opens in a new tab)
Common questions
Will you make me do something I have not agreed to?
No. Every exposure is chosen and agreed with you in advance, before it happens. I never use surprise, because surprise teaches you that therapy is unsafe, which is the opposite of what we need. You decide what the next step is and when you take it, and with children the steps are small enough to be achievable and chosen by the child wherever possible. My job is to make sure each step is useful, that a hidden compulsion is not cancelling it out, and that we move on from steps you already find easy.
Does ERP work if all my compulsions are mental?
Yes, but the mental rituals have to be identified first. Reviewing a memory, silently arguing with a thought, checking inside for a feeling of certainty, praying in a set way and mentally reassuring yourself are all compulsions, and they can happen hundreds of times a day without anyone noticing. If they carry on during exposure, they are likely to undermine it and it can look as though ERP has failed, so mapping them is often the most useful part of the early work.
How long does a course of ERP usually take?
There is no fixed number. NICE guidance (CG31) describes more than 10 hours of therapist time for OCD with a moderate impact on daily life, and more where the impact is severe. A long history, a lot of avoidance, or OCD alongside depression or another anxiety problem can take longer. I give you an estimate by the end of the first session, and sometimes further assessment is needed before I can. For children, the largest US trial of CBT for childhood OCD used 14 sessions over 12 weeks (Pediatric OCD Treatment Study, 2004). Sessions are weekly at first, then deliberately spaced out as you take over the work yourself. Family members joining in with rituals, or another difficulty alongside the OCD, can extend a course.
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Not sure whether this is the right fit?
Start with a free 20-minute call. We talk through what is going on, I answer any questions you have, and I tell you whether I think I can help. If I cannot, I will try to point you to someone who can. The call is free and there is no obligation to book.
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