Mental Health

An Update on the Poetry of Evidence-Based Psychotherapy for OCD


A student of Buddhism for many years once approached his mentor and asked for help understanding what it’s all about. The student complained that after all of his years of study, it still just seemed too complicated. Could the mentor please just boil it down to one simple statement that he can actually comprehend? The mentor thought for a moment and said, “Everything changes.” My approach to the treatment of OCD has also changed over the years. Like all evidence-based clinicians, my bias has been towards what makes the most sense based on the information I have in the present. As the information evolves, so do I. What stays the same in my approach (and that which I train my supervisees in) is what makes the most sense for now based on what we know now for the person whose suffering you are trying to relieve now. At The Retreat, where Sheppard Pratt’s Center for OCD and Anxiety team works within a residential program to help those with severe and complex OCD, I frequently encounter patients that are running low on hope. They’ve read the self-help workbooks and they’ve often received the “right” manualized treatments, but they haven’t yet been able to master their OCD. My ability to make a difference rests on my ability to maneuver around my timeline of clinical experience to find the combination of tools that make the difference.


I initially learned about OCD treatment in the traditional “gold standard” (meaning most tested and reliable over time) treatment for OCD, which is cognitive-behavioral therapy (CBT) with an emphasis on exposure and response prevention (ERP). Your client reports unwanted intrusive thoughts and strategies for dealing with them that are impairing functioning, so you take a look at how they may improve their thinking about the experience (cognitive therapy) and then collaborate with them on how to directly confront it behaviorally to overcome the related fear (ERP). This process of overcoming an obsession aimed for habituation, or the lessening of the anxious response to the trigger. We did this (and still do) by establishing a hierarchy of exposure challenges and tackling them one after the other, much like gradually increasing your max bench press at the gym.

In some of my early training, we modified the protocol to mindfulness-based cognitive behavioral therapy. Essentially, the idea was the same, to confront your fears methodically and aggressively, but with the emphasis on the endgame being accepting reality in the present moment. We took the C of CBT (cognitive therapy) and put a mindfulness bent on it by dropping all assessment of the probability of the content of fears being true and just focused on the fact that the nature of thinking was not objective. Traditional cognitive therapy tended to focus on spinning unhelpful or maladaptive thoughts into useful or adaptive ones, but those of us specializing in OCD recognized that this often spiraled into self-reassurance and other certainty-seeking efforts that actually maintained symptoms rather than alleviated them. We also took ERP and put a mindfulness bent on it. Rather than allowing patients to white-knuckle or hold their breath through scary exposures, we asked them to pay attention to the here-and-now, the thoughts, feelings, and sensations in the body, and let go of resistance to them as objects of attention. When we did imaginal exposures (writing out scary OCD narratives to practice being with them without ritualizing), we focused on exposure from the viewpoint that these stories were, in fact, stories and repeated engagement with them would reveal that. A trigger might pop up, the brain goes off into the OCD story, and then the patient recalls “Oh, yeah, there’s that story again” and drops it. This was an evolution from traditional versions of ERP that emphasized a kind of “make it worse to burn out the circuits” approach. It was not a softer approach by any means, but it moved the goal post from feeling less to being better at feeling more.

Acceptance and Commitment Therapy

A few years later, I started learning about ACT (Acceptance and Commitment Therapy). ACT shifted the focus from overt exposure (i.e., dominating the subject of your distress) to engagement with values, defusing from thoughts, and dropping the rope in the endless tug-of-war of the OCD mind (i.e., changing the subject). ACT prioritized psychological flexibility and building a life that was independent from the promise of habituating to fears. Plus, ACT was very well integrated in mindfulness concepts. What I discovered when incorporating more ACT-based language into my work with OCD clients was that very little changed but the language. I was asking people to take the risk of behaving as they would if they weren’t hostages to their OCD and asking people to behave in this way when they are being held hostage is, by definition, an exposure. Asking someone to stand up for a self that tells them to sit down is an exposure. It has been argued that ACT helps someone change their mind to change their behavior and ERP helps someone change their behavior to change their mind. In any case, the change in the language made all the difference for some of my patients that were struggling to change at all. And it all tracked with the available science of the time.

Inhibitory Learning

A few years later, I learned about inhibitory learning as an alternative way of thinking about what makes ERP effective. There was a fatal flaw in the habituation model in that it intentionally focused on distress/anxiety going down as the proof of success. This created two points of confusion for many OCD sufferers and therapists alike. First, wishing for distress to go down shared too much mental territory with the rationale for doing compulsions. Second, the habituation model seemed to overlook the fact that anxiety, disgust, and other forms of distress are normal, inevitable, and frankly, the spice of life. Who really wants to habituate to and be completely unimpressed with horror cinema or roller coasters? Inhibitory learning theory posited that ERP, done with some specific modifications to the traditional approach, paired the trigger with enough non-threat associations that the urge to flee from the experience with compulsions would go down whether or not the fear itself was extinguished. The model focused on anxiety tolerance, violating expectations of what one is capable of coping with, and mixing up exposure strategies in such a way that generalized to core fears. It also offered clinicians like myself (and my clients) some freedom from the sometimes confining nature of a strict exposure hierarchy.  Jumping around the hierarchy helped some people generalize and stop limiting themselves with narratives about what’s too hard or easy to do. It said, you could overcome your fear of just this doorknob by touching it a lot and not washing, but how about we overcome your unwillingness to feel contaminated by all things publicly touched? 

My teachers and mentors in the habituation model often referred to “small c, big B CBT,” meaning it’s fine to teach people about cognitive distortions, but the meat and potatoes of the work is in ERP. The inhibitory learning approach took this even further, specifically advising against any cognitive restructuring because it interfered in the surprise people get when they discover they are capable of confronting their fears. I’ve always had difficulty with this because my approach to cognitive therapy never weighed in on the probabilities or likelihoods of fears coming true. I just wanted my clients to see that there are more and less effective ways to think about things. In fact, recognizing all-or-nothing thinking or catastrophizing as inherently unhelpful opened people up to being fully in the moment with their exposures. As I incorporated inhibitory learning theory into my approach to ERP, I again recognized that the fundamental shift was not in what I was encouraging clients to do, but in the language I used to connect them to what they wanted to accomplish.

New Voices in the Evidence-based Chorus

I first heard about inference-based CBT (I-CBT) in the International OCD Foundation newsletter, Summer 2010. The article described some of the fundamental assumptions about how people walk themselves into obsessions and how they can walk themselves out. I didn’t hear much else about it until just recently when a few of my colleagues began referencing it in an online forum for OCD therapists. I decided to read I-CBT’s The Clinician’s Handbook for Obsessive-Compulsive Disorder by Kieron O’Connor and Frederic Aardema. I also read several studies and watched a few videos on what it’s all about.  

If traditional ERP (and to some extent ACT) made the C in CBT for OCD smaller, and inhibitory learning shrunk it even further, I-CBT is bringing it back in style as an overtly cognitive approach. Traditional cognitive therapy for OCD has always had the problem of relying on the OCD sufferer’s ability to challenge the likelihood of the content of their fears without engaging in self-reassuring compulsions. Mindfulness-based CBT addressed this by placing the emphasis on distorted thinking itself, labeling it, and abandoning it for something present-minded. In other words, “My fear is going to come true” becomes “I can’t predict the future and that makes me uncomfortable.” The false project of catastrophizing becomes the real project of recognizing rumination as a compulsion and reengaging with the here and now. I-CBT takes this concept a step further by positing that there is actually nothing to restructure in the first place. The problem isn’t that you are uncertain about your fear and need to live with it, the model suggests, but that you have no business thinking about it in the first place because it’s irrelevant. It’s the “oh come on now” approach to OCD treatment and there’s a lot to like about this.

Appraisal and Inference

Exposure-based treatment for OCD follows what is called an appraisal model. This means we understand unwanted thoughts to arise in consciousness on their own spontaneously and the problem being that people with OCD misjudge these thoughts as especially important or concerning. They feel an erroneous moral urgency to capture and eliminate these thoughts as threats. In contrast, Inference-based CBT follows, as you might expect, an inference-based model. This model suggests that unwanted intrusive thoughts are not arising randomly, but being inferred by following a train of thoughts that arrives there.  In other words, the obsessions are conclusions people with OCD come to because they are using an understandable but faulty reasoning process that they don’t use in other aspects of their life.  

Inferential confusion

Imagine someone with contamination OCD vs. someone who does not have this affliction. The appraisal model posits that the contamination OCD sufferer is touching an object that looks clean enough when all of a sudden a thought about it being contaminated springs into consciousness and demands to be dealt with. The inference model posits that this sufferer is touching the seemingly clean object when they wander off into a thought process and start building a case that it could be dangerous. They might think “other people have touched this object and may not have washed their hands” and “I read an article the other day about a parasite that gets under your nails and kills you” and so on. As the case is built, the OCD sufferer gets deeper and deeper into a story about being contaminated, built up entirely by ideas, not what they can observe right in front of them. They get confused, mixing in the awareness of touching the object with the story about the object that has nothing to do with the here and now. This is called inferential confusion. This kind of absorption into a completely self-constructed narrative happens to all of us when put in front of a really good movie or piece of music. We think something is happening besides actors on a screen or organized noise. But people with OCD have an easier time getting into these mental stories than getting out. So in simple terms, the appraisal model suggests OCD sufferers are being hit with unwanted thoughts and misinterpreting them while the inference-based model suggests OCD sufferers are unwittingly talking themselves into their unwanted thoughts. Or in even simpler terms, the inference-based model says the obsession comes from the doubt, not the doubt from the obsession.

Obsessional doubt

Back to our poor contamination OCD sufferer, the reasons they give themselves for remaining concerned are not the reasons they use for being concerned about anything else. I-CBT says this person who walked themselves into worrying about the contamination level of the object in their hands is using mentally constructed evidence that they would never use trying to cross the street. They’d look both ways and make a decision based on whether they saw an actual car coming, not based on whether they ever knew someone who got snuck up on by a Prius. This is the difference between normal doubt (concern based on common sense and the body’s senses in the here and now) and obsessional doubt (concern based on evidence collected from the imagination). The appraisal model doesn’t make this distinction as clearly and encourages the OCD sufferer to establish a more flexible relationship with doubt in general, regardless of theme. The inference-based model suggests there’s no reason to do this because normal doubt is worth attention and obsessional doubt is trash. The entire model rests on this concept and the entire treatment protocol can be boiled down to teaching people how to tell the difference.

The self-theme

Why does someone get inferentially confused around some themes and not others? In I-CBT, this issue is explored in something called a self-theme, quite similar to what other may call a core fear. I remember being in a graduate school class learning about the downward arrow technique. In the exercise I had to share a concern and my classmate had to keep incessantly asking “and if that’s true, then what?” until I either lunged for him or had a breakthrough. Well, it only took a few steps before I said, “Then I wouldn’t be worthwhile.” People audibly gasped. An old lady fainted. It was epic. Self-themes are the giant magnets in our narratives that pull in the content of our obsessions. OCD therapists have long said that OCD goes after what we care about the most, but the concept of the self-theme adds a bit to this theory by pointing out why we are sensitive to thinking our worst fears are coming directly for us personally.

Both the appraisal model and the inference-based model have a lot of evidence backing (though the appraisal model has been around longer and therefore studied more). Some may view these as opposing concepts, rather than complementary ones, but I think that misses the mark. For many with OCD, both experiences are happening simultaneously. I’ve built an entire career out of learning to manage the random unwanted mental junk mail that clogs my consciousness spontaneously and am also the first to admit that I sign up for mental mailing lists by spending way too much time in the land of imagination.


In my training and studies, part of ERP always included working with and attempting to increase tolerance of uncertainty. The reason why trying to prove your obsession untrue didn’t work is that anything can be technically true. ERP never aimed to eliminate the uncertainty because that is the one thing that is impossible. Many people are averse to accepting uncertainty despite it not being optional.  How does a new mother accept uncertainty about harming her baby? How does a religious person accept uncertainty that they’ve insulted their higher power and could be punished? Yet much of this resistance is linguistic in nature. Accepting uncertainty doesn’t mean concluding that the most terrifying things are a 50/50 split and that we should worry about every idea as if it were. It means the opposite, that when you buy a lottery ticket, you shouldn’t expect to win, even though anything is possible. When you have an intrusive thought, you don’t have to be certain about it to let it go. Confidence and feeling as if knowing has to be good enough when certainty is an illusion.

I-CBT points out that you can know you’re not going to turn your car into oncoming traffic as confidently as you can know the chair you’re sitting on is not a crocodile. I-CBT still doesn’t offer certainty because I-CBT isn’t concerned with what is possible or not. Its literature acknowledges that what OCD sufferers worry about often does exist in the realm of possibility. But its only concern is with relevance to the here and now. It says we don’t need to overtly accept uncertainty because we don’t need to think about uncertainty at all. In other words, a meteor could be headed towards my house as I write this but that has nothing to do with getting this blog finished. More to the point, the mental system I use to determine that I should be banging away at the keyboard right now instead of cowering in the basement (that would work, right?) is perfectly intact. I see the laptop in front of me, I feel the keys on the two fingers I use to type, I hear the washing machine in the background and the kids fighting upstairs, and I have all the information I need to finish this senten---akfjhlhf;dslj’fj’lfj’sdjfs,m,c,xxzfdddf… just kidding. I have all I need to know where my attention belongs and I don’t have to actively engage with the concept that a meteor might be heading my way.

An Alternative to ERP?

The language in the OCD treatment community around I-CBT being an alternative to ERP can be confusing (for patients and providers alike). While I-CBT is a standalone treatment protocol, from what I have seen so far, my sense is that I-CBT has more in common with ERP than one might assume. We just have to remember that how ERP is practiced has evolved quite a bit over the years. I-CBT certainly does not work on intentionally increasing distress or use over-correction the way traditional ERP can, but it does ask people to run behavioral experiments that involve being where their fear arises and resisting compulsions. I would also argue that a true cognitive approach to OCD is also a behavioral approach to OCD because in OCD, the cognitive is the behavioral. The way people think and the way they apply their attention to their thinking are behavioral acts. Mental rituals are behaviors. Investing in or ignoring cognitive distortions are behaviors. Choosing behaviors that are the opposite of what OCD demands is exposure, regardless of the rationale. Anything an OCD sufferer is asked to do in treatment besides compulsions is inherently an exposure to them. I-CBT provides truly wise techniques for justifying a complete disregard for OCD’s demands, but it still invites you to turn away from the beast, which requires no less bravery and no less willingness to risk it all.

Importantly, I have found some clients get caught up in a mentality of “exposing away” distress through behaviors that look like ERP but are no less compulsive. If I put my hand in the toilet and then touch all of my possessions, then I know I’m fighting my OCD and don’t have to worry about whether things are contaminated. This mentality misses an essential part of OCD therapy, not playing OCD’s game. The actual exposure that is most effective in many cases is exposure to the fear of not having done enough! In other words, noticing the thought that I may have become contaminated and may spread it, then shrugging that off as an irrelevant doubt and going about my own business can be a boss level exposure. I-CBT does an excellent job of articulating how to do this and, frankly, I think it’s good ERP.

Therapy is Poetry

As I learn more about I-CBT, I have already started to incorporate it into my treatment approach. It hasn’t been any more of an adjustment than adding mindfulness, ACT, or inhibitory learning. I was already instructing clients not to weigh in on the probability of their fears being true. I was already instructing them to recognize when they were using distorted thinking patterns to convince themselves to worry about absurd ideas. I was already telling them to see their ruminations as stories and to drop their stories (a phrase I learned on meditation retreat). But now I have another useful pivot I can make in helping people with OCD who still feel stuck.  

Patients are not their diagnoses and therapists are not treatment manuals. Both are people, and people, like science, evolve. Let’s cut to the chase, compulsions bad. There’s your OCD treatment protocol. But if someone has received a lot of OCD therapy and they still find compulsions to be a better deal than the alternative, then the failure is not on them. The failure is not on the treatment approach either, whether it’s traditional ERP, I-CBT, or everything in between. The failure is in the therapist and the patient to find a language that makes sense to both. Many of my patients speak fluid ERP, conversational ACT, and a smattering of inhibitory learning. Now some of them will also find the vocabulary of I-CBT makes the poetry of therapy work. As the great poet John McLane once exclaimed, “Welcome to the party, pal!”


For further reading:

Aardema, F., Bouchard, S., Koszycki, D., Lavoie, M., Audet, J-S, O’Connor,K. (2022). Evaluation of inference-based cognitive-behavioral therapy for obsessive-compulsive disorder: A multi-center randomized controlled trial with three treatment modalities. Psychotherapy and Psychosomatics.

Abramowitz JS. (2006). The psychological treatment of obsessive-compulsive disorder. Can J Psychiatry. 51:407–16.

Craske MG, Treanor M, Conway CC, Zbozinek T, Vervliet B. (2014) Maximizing exposure therapy: An inhibitory learning approach. Behav Res Ther. 58:10–23. 

Foa EB, Yadin E, Lichner TB. (2012). Exposure and Response (Ritual) Prevention for Obsessive Compulsive Disorder: Therapist Guide. USA: Oxford University Press.

Grayson, Jonathan. (2010). OCD and Intolerance of Uncertainty: Treatment Issues. Journal of Cognitive Psychotherapy. 24. 3-15.

Hershfield, J, & Corboy, T. (2020). The Mindfulness Workbook for OCD: A Guide to Overcoming Obsessions and Compulsions Using Mindfulness and Cognitive Behavioral Therapy, 2md ed. New Harbinger Publications

O'Connor, K., & Aardema, F. (2012). Clinician's handbook for obsessive compulsive disorder: Inference-based therapy. Wiley Blackwell.

O’Connor, K., & Aardena, F. (2010).  Inference-based Therapy for Obsessions. OCD Newsletter, Vol. 24 (3), International OCD Foundation

Twohig MP, Abramowitz JS, Bluett EJ, Fabricant LE, Jacoby RJ, Morrison KL, et al. (2015). Exposure therapy for OCD from an acceptance and commitment therapy (ACT) framework. J Obsessive Compuls Relat Disord. 6:167–73.

Meet the Author

  • Jon Hershfield, MFT

    Director, The Center for OCD and Anxiety
    Anxiety Disorders, Cognitive Behavioral Therapy, Obsessive-Compulsive Disorder (OCD)