People with obsessive-compulsive disorder (OCD) who believe in the effectiveness of their therapy are significantly more likely to experience improvement, according to a major study published this week. The findings were published in the journal BMC Psychiatry.

Researchers in Norway assessed 163 adults with difficult-to-treat OCD who had either relapsed or failed to respond to previous treatment. All participants underwent a four-day intensive cognitive behavioural therapy (CBT) programme known as concentrated exposure therapy (cET), which included individual and group sessions. Before treatment began, patients completed a questionnaire that measured their belief in and expectation of the therapy’s effectiveness.

The results showed a clear link between positive expectations and successful outcomes. Patients who scored higher on the Credibility/Expectancy Questionnaire (CEQ) tended to report fewer OCD symptoms after therapy and continued to show improvement 3 months and even 1 year later. Importantly, these associations held true even after accounting for factors such as age, gender, and pre-treatment levels of anxiety and depression.

Researchers found that patients with the highest belief in the treatment were far more likely to benefit. More than 87% of those with high expectancy scores experienced a positive treatment response, compared to just over half among those with low scores. The findings suggest that attitudes towards treatment can play a pivotal role, even in cases where past therapy attempts have failed.

The Bergen 4-day treatment (B4DT) programme used in the study has previously shown promise in helping patients make rapid gains, particularly through its emphasis on exposure and response prevention. In this study, nearly 70 percent of participants had additional mental health conditions, with generalised anxiety and depression being the most common. Despite this, the concentrated therapy approach proved effective for most.

Participants rated the treatment as highly credible, with average scores nearing 90 out of 100. Many reported feeling motivated and confident in their ability to commit to the programme. These self-assessments were not simply expressions of hope. The study demonstrated that patients’ initial beliefs had a measurable impact on symptom reduction and social functioning outcomes.

Work and social adjustment also improved significantly for those with strong treatment expectancy. While the effect was smaller than for OCD symptom reduction, the trend was consistent and meaningful. Patients who had previously struggled with work or social relationships reported greater improvements if they began treatment with higher levels of belief in its success.

The findings point to the value of assessing and addressing patients’ expectations early in therapy. When patients feel that a treatment makes sense and will work for them, they are more likely to engage fully and benefit from the process. This could mean that before therapy even begins, clinicians may need to spend more time helping patients understand and commit to the treatment plan.

The research also raises questions about how previous treatment failures are framed in therapy. Rather than eroding hope, past experiences might be used to refine new approaches and enhance credibility. For those struggling with OCD, the study offers a hopeful message: belief in a treatment is not just wishful thinking, but a predictor of meaningful progress.