By Richard Gallagher, LMFT

This article was initially published in the Spring 2023 edition of the OCD Newsletter. 

DISCLAIMER: I am a licensed psychotherapist with both clinical and lived experience with this issue — and a trained OCD specialist — but this article is based on personal conclusions and opinions informed by recent literature. More research is always necessary on the subject of this article. Please discuss any treatment strategy with a mental health professional.

For the sake of simplicity, I equate exposure and response prevention (ERP) here with “directly exposing yourself to a trigger and trying to get used to it.” In reality, ERP is more nuanced than this definition and involves many distinct elements. For a more detailed description of ERP, please visit the “Exposure and Response Prevention (ERP)” page on the IOCDF site. My simplistic definition of ERP in this blog reflects the gist of my personal experience of being treated (ineffectively) in the past by trained ERP specialists.

If you suffer from OCD, the “gold standard” for treatment is exposure and response prevention (ERP). Its name is also its strategy: expose yourself to whatever it is you fear, and don’t respond to it. For example:

• If you have an intrusive thought, don’t try to neutralize it or furiously Google for reassurance.
• If someone or something triggers you, don’t avoid interacting with them or it.
• If you have contamination fears, touch things that feel contaminated and don’t wash afterward.

The goal of ERP is to either get used to what you fear (habituation), or at least learn to tolerate the distress it causes and live with it (acceptance).

This approach works well for many people — but not everyone. Here, I want to focus on one type of OCD that classic ERP often isn’t particularly effective for, according to a growing body of research — and one that I suffer from myself: contamination OCD triggers based on disgust.

This research shows that ERP treatment outcomes for disgust are mixed at best, and that gains from treatment aren’t durable^1,2,3. As a sufferer and a clinician, I believe I know why this is the case: ERP was designed to treat fear, not disgust, and doesn’t reflect our real-life approach to managing disgust. So I am going to discuss one possible way to tweak ERP to make this issue much more treatable.

Why disgust and fear are different: A neurobiology lesson

All contamination triggers are not the same. Some are based on fear (“I’ll get sick and die from germs!”), but others are based on disgust (“I’ll never feel clean enough and will obsess about this forever!”).

Both of these are very uncomfortable, but according to recent research, they spring from different neurological reactions. Fear is triggered by that part of your brain known as the amygdala, a brain region associated with strong emotions in response to threats; it responds to an urgent and immediate threat such as a hungry bear, so you can fight or run away from it. Exposure will often eventually extinguish unrealistic fears, or teach you to tolerate them better.

Disgust, on the other hand, is processed by a different part of the brain known as the insula. It processes sensations of disgust and stores them in our long-term memory, to keep us from being poisoned by things like eating spoiled food, breathing in bad air, or spreading noxious substances on your hands. Disgust doesn’t change easily, no matter how much exposure you do. And when change happens, it happens very s-l-o-w-l-y.

For many of us, using ERP as a blunt instrument to treat disgust exactly the same way as fear often backfires. When you expose yourself to something disgusting, the feeling of disgust often doesn’t change over the course of the exposure, nor does your tolerance of it. In fact, as you stick out these exposures, your revulsion or distress tolerance may even get worse. As much as we wish that the amygdala and the insula would behave the same way, they are separate brain regions and  stubbornly do not.

I cannot overemphasize enough the importance of how slowly disgust changes. It usually doesn’t change over hours or days — often it’s more like months, years, or never. Numerous therapists have told me privately that they’ve had clients expose themselves to triggers for months on end with no progress. This is why many sufferers find exposure therapy to be exactly like an average person smearing dog poop on everything they own, trying to get used to it, and then discovering that they can’t.

In my view, this analogy to dog poop is what may hold the key to successful treatment. Now, let’s explore this process in more detail.

How people normally adjust to fear versus disgust

People do get used to both fear and disgust in real life, but these are very different processes.

First, let’s look at fear. Remember when you first rode a bicycle? It was scary! But your parents probably encouraged you, you took small steps, and eventually, whee! It wasn’t as scary anymore. With enough practice, your brain reconceptualized this as being less scary and your fear diminished over time. This is exactly why ERP works so well for so many OCD fears and intrusive thoughts.

Unfortunately, this model doesn’t work the same way with disgust, because disgust is much more stubborn and hard to change. Let’s look at an example of how many veterinarians — a profession someone once described as “a flash flood of poop” — actually get used to dog poop. At first, contact with poop feels terrible. New vets may use lots of safety behaviors, such as wearing gloves, washing their hands every five minutes, and avoiding whatever they can. However, their response to this is to continue to practice veterinary care versus actively trying to confront the poop. And, in time, they learn to reduce the accommodations they need to do this because they put themselves back into the situation every day and these triggers eventually soften, over a l-o-n-g period of time. During the first month, vets may wash their hands constantly. Six months in, it’s uncomfortable, but they’re more used to it. After a year, they still don’t like poop (and probably never will) but when the inevitable happens, they shrug, clean up, and move on. The exposure — and the habituation — isn’t to poop: poop is as disgusting as ever. The exposure is to being a veterinarian, and doing what veterinarians do every day, in the presence of poop.

This is precisely how most people learn to manage disgust in normal life. Paramedics don’t spend all day hanging around dead bodies to get used to them — they keep working as paramedics. New mothers don’t stick their hands in a pail of dirty diapers — they keep changing their babies. Sanitation workers don’t roll around in garbage — they keep going to work. In other words, they live their lives, do whatever they need to do, and over a long enough period of time, it gets easier and they need fewer accommodations.

By comparison, classic ERP would be like having these veterinarians carry a lump of dog poop around in their hands and not wash their hands, until they get used to it. (Or more realistically, perhaps carry around a tissue contaminated with dog poop — an actual exposure some clinicians have proposed for contamination fears.)

Some of these vets might get used to the poop, but this won’t happen quickly — and many of them will never get used to it. (I suspect that even seasoned vets would still avoid sitting in a chair with visible poop on it.) Some of them may find that they actually get worse, particularly if they cross-contaminate more things, and feel even more closed in. Quite a few of them will “flunk” this exercise, and perhaps even decide that they aren’t cut out for the field. (P.S. I “vetted” this section with an experienced veterinarian who agrees with everything here.)

This is often what happens in general when you use ERP for disgust-based triggers. It works for some people, but head-on exposure to triggers will still fail others or even make them worse. These people may even be dismissed as “treatment failures” when, in fact, the problem may actually be the treatment approach itself. It isn’t the same as, say, dealing with a fear by facing it head on, because disgust stimuli change much too slowly.

Now, let’s look at a strategy for treating disgust-based OCD that has worked, for myself and others:

Do whatever you need to comfortably get into disgust-inducing situations for a l-o-n-g enough period of time for your response to your triggers to soften. Then, gradually reduce your accommodations.

Let’s call this a “mastery” approach versus an exposure approach. Your goal is to master situations you avoid, even when your triggers may still remain disgusting for a very long time. Most importantly, you aren’t trying to expose yourself to discomfort — you are trying to be comfortable enough to do lots of practice for a long time. In other words, the focus is on the RP (response prevention), not E (exposure).

Let’s compare common wisdom from ERP about contamination fears with a mastery approach: