How we treat obsessive–compulsive disorder (OCD) with CBT

Obsessive–compulsive disorder (OCD) affects 1–2 % of the population but is often missed in primary care. The treatment recommended in Socialstyrelsen’s national guidelines is CBT with exposure and response prevention, ERP. Here is what the work looks like in practice, from the initial assessment to follow-up a year later.

Detecting OCD – assessment in primary care

OCD often hides behind anxiety, depression or sleep problems. Patients rarely volunteer information about obsessive thoughts: they feel ashamed of them or believe they are "going mad". Our first task is to ask the right questions.

• "Do you have recurring thoughts, images or urges that feel intrusive and that you cannot let go of?"
• "Do you do things over and over again to ease your anxiety – washing, checking or repeating things in your head?"
• "Do you avoid places, people or situations to escape obsessive thoughts?"
• "Do these patterns take up more than an hour a day in total?"

When OCD is suspected, the Y-BOCS (Yale-Brown Obsessive Compulsive Scale) is used to measure symptom severity. The original version of the Y-BOCS has a total score of 0–40. Common interpretation ranges for adults are 0–7 subclinical, 8–15 mild, 16–23 moderate, 24–31 severe and 32–40 very severe OCD. The score does not replace clinical assessment. The scale is used both for assessment and as an outcome measure during treatment.

Case formulation: understanding what maintains the symptoms

A good case formulation for OCD should answer three questions: What are the obsessions about (which category, and what's the "worst-case scenario")? Which compulsions, visible or mental, does the patient use to reduce the anxiety? And what does the patient avoid altogether to steer clear of the situation?

Treatment: ERP step by step

The core method is exposure and response prevention (ERP). The patient faces what triggers the obsessions and at the same time refrains from the compulsion. When the anxiety is no longer met with a ritual, the patient gains new experiences of the situation, for example that the discomfort is bearable and that the feared outcome rarely happens.

1. Build an exposure hierarchy

Together with the patient, you list 10–15 situations, ranked by anticipated anxiety (0–100). For contamination-related OCD, the hierarchy might range from touching a clean table (30) to eating a sandwich without washing their hands after using public transport (95).

2. Carry out exposure during sessions

Initial exposures are planned together and may be carried out with the therapist when appropriate. Exercises target excessive rituals while following reasonable hygiene and safety practices. Exposure takes place in real situations – toilets, door handles, public transport – and the patient refrains from both visible and mental rituals. Anxiety and new experiences are reviewed in a way that suits the patient, so that the ratings do not become a ritual in themselves. The therapist refrains from reassuring, since that works as reassurance-seeking, and instead supports the patient in staying in the situation.

3. Plan regular homework

ERP rarely works well without regular practice between sessions. Therapist and patient draw up a weekly plan covering which exposures to do, how often and for how long, and which mental compulsions the patient should refrain from. The patient records their anxiety and notes what turned out differently from what they had expected.

4. Address mental compulsions

A large part of the difficulty in OCD treatment concerns compulsions that take place in the mind: mental reviewing, comparing and self-reassurance ("it's fine, I've already washed twice"). The patient learns to notice these mental rituals and to refrain from them in the same way as from the visible ones. If they continue, the anxiety is quietly relieved and the exposure loses much of its effect.

Common pitfalls in treatment

• The therapist reassures the patient during exposure. The reassurance then works like a safety behaviour and weakens the learning.
• Moving up the hierarchy too slowly. The patient stays too long on easy steps and never tries the situations that cause the most anxiety.
• Family members continue to take part in compulsive behaviours (family accommodation). This should be identified and addressed early, often with separate conversations.
• Depression or ongoing substance misuse is missed at assessment and makes treatment harder.

Combining treatment with medication

In moderate to severe OCD, SSRIs (e.g. sertraline or fluoxetine) at high doses can be given as a complement, prescribed by a doctor. However, ERP remains the first-line treatment even in severe OCD, and combination treatment is particularly relevant when the patient cannot manage to begin treatment with psychotherapy alone. Our role as CBT therapists is to collaborate with the prescriber, not to prescribe ourselves.

Ending therapy and follow-up

We allow 14–20 sessions for uncomplicated OCD, sometimes with more frequent contact at the beginning and less towards the end. The final sessions focus on maintaining progress: a written plan for what the patient will do if symptoms creep back, independently completed exposure exercises, and follow-ups at 1, 3, 6 and 12 months.

Frequently asked questions