How to Build and Refine Your Exposure and Response Prevention (ERP) Hierarchy

Exposure and Response Prevention (ERP) is widely recognised as the gold-standard treatment for Obsessive-Compulsive Disorder (OCD). It’s endorsed by top organisations like the National Institute for Health and CareExcellence (NICE) and the International OCD Foundation (IOCDF) for its effectiveness in reducing symptoms. Possibly because so many people read about the model on the Internet or self-help books, more and more people are looking for strategies to help themselves, or to complement treatment with their psychologist. For this reason, I try to write as many practical articles that will help those who are motivated to put the work in. Today I will be looking at a very specific aspect of ERP; namely the exposure hierarchy. If you’re new to ERP or looking for a foundational understanding of how it works, the following articles can give you background knowledge.

• MoodSmiths Complete Guide to Exposure and Response Prevention
• The Rationale Behind ERP, and
• Who can benefit from ERP.

Why Hierarchies Matter

An ERP hierarchy is essentially a roadmap that ranks your OCD triggers from the least anxiety-inducing to the most challenging. Here’s why it’s indispensable for managing OCD:

1. Progressive Learning: By starting at lower-level fears, you gain confidence and skills that help you face more intense triggers later.
2. Avoiding Overwhelm: Jumping straight to the scariest situation often results in extreme anxiety. I once worked with a client, let’s call him Tom, who attempted to tackle his top fear—touching public toilet surfaces—on day one. Without preparation, he became overwhelmed and nearly quit ERP altogether. We reset, built a graded hierarchy, and he successfully worked his way up to that public restroom challenge over time.
3. Structured Exposure: A hierarchy ensures you practice ERP exercises in a planned, consistent manner—vital for long-term results.

Step 1: Brainstorm Your Fear Triggers

To build a meaningful hierarchy, you first need a comprehensive list of OCD triggers. These could be situations, thoughts, images, or physical objects that spark anxiety and drive compulsions.

• Prompts to Get You Started:
  • Which situations do I avoid due to fear of contamination, harm, or other worries?
  • When do I feel most compelled to check or seek reassurance?
  • What specific intrusive thoughts occur throughout the day?

Step 2: Rate Distress Accurately

After brainstorming, rate each trigger on a distress scale. A commonly used metric is Subjective Units of Distress (SUDS), which can be 0–10 or 0–100. For instance:

• 0 = No discomfort whatsoever
• 10 (or 100) = The most intense anxiety you can imagine

Tips to Stay Objective

• Daily Variation is Normal: Anxiety levels can fluctuate; aim for an average rating.
• Use Clear Benchmarks: If “10” is “extreme panic” for you, define what that looks like (e.g., heart pounding, racing thoughts, urge to escape).
• Update Over Time: Don’t be surprised if a 5 becomes a 3 after consistent exposure work.

This rating step ensures your hierarchy accurately reflects the true intensity of each fear, making your exposures more effective.

Step 3: Organise & Prioritise Your Triggers

Now, arrange your triggers from least to most anxiety-inducing. This is your ERP fear ladder. Below is a sample table with different items than I’ve used in previous guides—tailor yours to your unique situation.

By starting from the lower SUDS items and moving up, you can systematically build tolerance for anxiety.

Step 4: Refine and Adjust as You Go

Your exposure hierarchy is not set in stone. As you begin exposure exercises, your comfort levels may shift. That’s perfectly normal—OCD triggers can evolve, and your resilience may grow.

• Difficulty Levels: If an exposure is too easy, move up a step sooner. If it’s too daunting, break the step into smaller sub-steps.
• New Fears & Insights: Sometimes, new triggers reveal themselves once you start tackling old ones. Add them to your hierarchy in the appropriate spot.
• Track Your Progress: Keep notes on each exposure session, including how long you stayed in the situation and your anxiety ratings over time.

At MoodSmith, I offer online self-help programs that integrate ongoing tracking tools to make it easier to adjust your hierarchy and maintain momentum.

Common Mistakes to Avoid

1. Jumping Too High, Too Fast
   • If you go straight to your most feared trigger, you risk overwhelming yourself. Stick to your graded plan.
2. Invisible Mental Compulsions
   • Compulsions aren’t always physical. Mental reassurance, silent counting, or “thought neutralising” can derail your progress. Awareness is key.
3. Leaving Too Soon
   • Allow your anxiety to peak and then subside naturally—don’t flee the exposure at the first sign of discomfort. Remember, the goal is to learn you can handle the distress without resorting to rituals.

For more tips on managing anxiety during exposures, the Anxiety & Depression Association of America (ADAA) offers additional resources and research-backed strategies.

FAQ

1. How long do I practice each level?
Stay in the situation until your anxiety drops by at least 50%. This may take a few minutes or longer. Repeated exposure across days or weeks can further reinforce the lesson that you’re safe without compulsions.

2. Can I work on multiple triggers at once?
Focus on one or two triggers at a time for best results. Overloading yourself can make it difficult to track progress or manage your anxiety effectively.

3. What if my fear is purely mental or “thought-based”?
That’s where imaginal exposure comes in. Write a detailed script or record an audio narrative describing the feared scenario. Review it repeatedly, resisting mental rituals or “thought cancelling.” People with what has been called ‘Pure O‘ often think that they do not have compulsions, but they will be there, they might just be covert compulsions, where you do something to neutralise your anxiety but other people could not see it; like silently repeating a phrase.

Conclusion & Next Steps

Designing and refining an ERP hierarchy is a cornerstone of successful OCD treatment. By identifying triggers, rating your distress, and tackling each step in a measured, consistent way, you give yourself the best chance of long-term improvement.