Introduction: Overview of obsessive-compulsive disorder 

When many people hear about Obsessive Compulsive Disorder (OCD), they think of someone who is very organised or very clean, they may even relate to these descriptions and label themselves as a ‘bit’ OCD. However, OCD is not a spectrum that we all fall on. Named one of the top ten disabling disorders by the World Health Organisation (WHO),¹ it is unfortunately more serious than being overly eager to be clean and organised than the average person
When someone has OCD, they have obsessions and/or compulsions. Obsessions are repetitive and persistent thoughts or impulses. They are usually unwanted and can cause anxiety and distress. These obsessions can last all day and persist every day. Whereas compulsions are repetitive behaviours or mental acts that the individual feels driven to perform. An example of this would be counting to 10 before opening any door. 

OCD can make someone’s life very restricted and difficult. Other psychiatric conditions and health issues can develop alongside, such as depression. In fact, the suicide attempt rate is 10 times higher than in the general population, at over 14%. 

The contents of the obsessions and compulsive acts seen in OCD can include anything. However, there are certain obsessions and compulsions that are commonly seen paired together. These include:²

Cognitive behavioural theory suggests that the compulsions are a response to the obsessions; however, their exact relationship is not fully understood.² 

To see what OCD is like through the eyes of someone with the condition, here is a video uploaded by Demystifying Medicine McMaster showing that.

Exposure response prevention as a treatment approach

First-line treatments are treatments initially recommended for treating OCD. Cognitive behavioural therapy (CBT) with exposure response prevention (ERP) is one of these first-line treatments, or treatments that are recommended to start with when treating OCD, including Cognitive behavioural therapy with Exposure Response Prevention therapy (also known as exposure and ritual prevention). Selective Serotonin Reuptake Inhibitors (SSRIs) are a type of medication which increases serotonin, known as the 'happy' chemical in the brain. Having more of this chemical is thought to help reduce the intrusive thoughts in OCD. By combining their use with ERP, this can boost the effects of treatment.²

Overview of ERP

Depending on where you are in the world, ERP may be seen as a type of CBT or a part of CBT. ERP can also be used in combination with CBT. Like other forms of CBT, it is performed by a licensed mental health professional such as a psychologist, social worker or mental health counsellor. The overall goal of ERP is to challenge how the person responds to the distress associated with the trigger. Eventually, they learn that the feared trigger is safe, preventing the compulsion.   ERP involves repeated exposure to the OCD trigger, combined with guidance on how to avoid performing the compulsive behaviour.³

The treatment can be broken down into 3 components:³

• Psychoeducation: learning about mental health, OCD and treatments
• Exposure: confronting fears and discomfort associated with obsession 
• Response prevention: learning how to resist performing a compulsion 

Psychoeducation 

Psychoeducation in ERP serves very similar functions as in many other psychological treatments. Firstly, it provides reassurance that the individual has a known condition and that there are evidence-based treatments available. Secondly, it helps set realistic expectations for therapy.  Finally, psychoeducation enhances the individual's understanding of the relationship between thoughts, behaviours and emotions. The interactions between these three components are known as the cognitive triangle and are fundamental for CBT.⁴ 

The exposure component

Fundamentally, the exposure components involve purposefully confronting fears and sitting with obsessive thoughts that come up. There may be differences in how therapists carry this out. This ultimately depends on their clinical judgement and the individual's situation. Over time, this can reduce the anxiety that the feared thing creates. It is often done gradually, starting with a level of exposure that causes a manageable level of anxiety, before advancing on to more demanding exercises.

Without being exposed to these fears in OCD,  a person may feel as if they can never handle the situation, and the obsession would remain, or even get worse. It’s also important to note that simply provoking the obsession once and for a brief period of time is not enough. This exposure must be done repeatedly and for extended periods of time to really overcome the fear.⁶

There are 4 kinds of exposure that may be used: 

1. In vivo exposure: staying in the presence of the feared object/situation (eg/ contaminants) for longer and longer periods of time
2. Imaginal exposure: mentally visualising yourself in feared situations or visualising the consequences of feared situations (e.g. visualising accidentally injuring someone)
3. Interoceptive exposure: using exercise (eg/ hyperventilating) to deliberately evoke feared bodily sensations (e.g. shortness of breath)
4. Virtual reality exposure: simulating the feared situation using virtual reality technology (e.g. a flight simulator)

As an example of in vivo exposure, someone with OCD has a fear of contamination in public bathrooms. They may be asked to repeatedly stay in a public bathroom and perform various triggering actions. If, for example, they have a specific fear of being contaminated by the floor, they may be asked to sit down on the floor for longer and longer periods of time. ⁶

 In some cases, in vivo exposure may not work as the person’s fear may be impractical to simulate. Instead, imaginal exposure may be used as a stepping stone or replacement.

Moreover, while gradual exposure to the fears is usually preferred by patients, ⁵there are 3 different pacing strategies that can be used: 

1. Graded exposure: the mental health professional works with the person with OCD to construct an exposure fear hierarchy, where feared things are ranked according to how feared they are by the individual with OCD. Exposure then starts with the things at the bottom of the hierarchy before working their way up
2. Flooding: the fear hierarchy is also constructed like in graded exposure, but exposure starts with the things at the top of the hierarchy instead
3. Systematic desensitisation: exposure is combined with relaxation techniques to make the anxiety during exposure more manageable

Prevention

Despite compulsions providing immediate relief, they reinforce the fear and avoidance of any situations that may be triggering, leading to a restricted life. Prevention aims to stop this compulsion, even when the urges are still there, teaching the individual to tolerate the distress without performing the compulsion or avoiding the trigger.⁶

Following each exposure session, the practitioner and patient review what happened, how the individual with OCD’s expectations compare to the observed consequences, and what was learned. Towards the end of the course of ERP sessions, they will also work together to plan how to prevent relapse.⁶

Effectiveness and validity 

Evidence of the effectiveness of ERP in treating OCD

The effectiveness of Exposure and Response Prevention for OCD has been firmly established through randomised controlled trials, including highly selective and more diverse samples. It is important to know that trials with highly selected samples may not fully represent the wider population. The diverse samples encompass patients with complex histories, including those with additional psychiatric disorders and those undergoing medication. Across these studies, ERP consistently demonstrates high efficacy in treating OCD.⁶

 Even though ERP is an effective first-line treatment for OCD, only around half of patients will become completely symptom-free after treatment. This may be due to a variety of factors, including symptom severity, motivation for the treatment and differences in how ERP is conducted by the practitioner.⁷

How does ERP work?

The psychological mechanisms behind ERP’s effectiveness are unclear. Initially, it was thought that habituation ‘extinguishes’ the conditioned fear response, whereby ERP breaks the two fundamental associations that occur in OCD.  These include the association between distressing sensations and their triggers and the association between performing the compulsions and alleviating symptoms of distress.⁶

However,  research now points to an ‘inhibitory learning model’ where new information learnt can block out, rather than ‘erasing’, obsessional thoughts/urges. In other words, even though the old thinking habits are still there, new thinking habits can override the old ones.³

FAQ’s

Where can I find more information on OCD?

More information from OCD experts, many of whom also have OCD, can be found on the website for the International OCD Foundation, here.

How many sessions are needed?

While the most efficient frequency and number of ERP sessions may vary depending on the individual, 90- to 120-minute sessions once or twice per week, for a total of 12–20 sessions, is a commonly used range.⁵

Summary

Obsessive-Compulsive Disorder is a serious psychiatric disorder involving persistent thoughts and compulsions. It is associated with a heightened suicide risk and often accompanied by other psychiatric conditions. ERP, a first-line OCD treatment, involves psychoeducation, diverse exposure techniques such as in vivo and imaginal reality), and response prevention. Exposure aims to reduce the distress of the triggering situation so it can be tolerated and is structured in different ways. This can include graded exposure, flooding, and systematic desensitisation. Prevention focuses on resisting compulsions and collaborative relapse prevention planning. While ERP is highly effective, complete symptom relief is not guaranteed for everyone