Cognitive behavior therapy in the treatment of irritable bowel syndrome

Sammanfattning: Background: Irritable bowel syndrome (IBS) is a disorder characterized by abdominal pain or discomfort combined with altered bowel habits and is associated with impaired quality of life. The prevalence of IBS in the general adult population is approximately 10%. Psychological factors have been implicated in IBS because of high rates of comorbidity with psychiatric diagnoses and the fact that stress can cause IBS symptoms. Several studies have been conducted on psychological treatment for IBS. Most of these have studied cognitive behavior therapy (CBT) but show inconsistent results. Although symptom-related fear and avoidance behaviors have been found to play an important role in IBS, no psychological treatment has targeted these factors primarily. The “third wave” of cognitive behavioral therapies promotes acceptance and behavioral flexibility in the presence of aversive experiences, such as IBS symptoms. Exposure treatment is a behavioral intervention aimed at decreasing fear of arbitrary stimuli. Given the high prevalence of IBS, there is need for delivery formats that allow more patients to gain access to treatment. Internet-delivered cognitive behavior therapy with online therapist support has shown effectiveness in treating both psychiatric disorders and disorders within the behavioral medicine field. Aims: The general aim of the present thesis was to develop and evaluate an effective psychological treatment for IBS that can be made accessible to a large number of IBS patients. We developed an exposure-based CBT treatment that emphasized acceptance and behavioral flexibility in response to IBS-related experiences. Specific aims of this thesis were to: a) evaluate exposure-based CBT as a group treatment for IBS (study I), b) evaluate exposure-based CBT delivered via the internet (ICBT) for IBS (study II), c) evaluate the long-term effectiveness of ICBT for IBS (study III), d) evaluate the effectiveness and clinical utility of ICBT for IBS (study IV), and e) evaluate the specificity of ICBT for IBS (study V). Methods: Study I included 34 referred female IBS patients who underwent exposure-based CBT in group format. Study II randomized 85 self-referred IBS patients to ICBT or waiting list. Study III was a long-term follow-up of study II, 75 of the original study’s 85 participants (88%) participated in the 15- to 18-month follow-up. Study IV randomized 62 consecutively recruited patients at a gastroenterological clinic to ICBT or waiting list. Study V randomized 195 self-referred IBS patients to ICBT or internet-delivered stress management. The stress-management condition was designed to control for effects of treatment credibility, expectancy of improvement, and attention from a caregiver. The treatment conditions in all studies lasted for 10 weeks. Results: In all studies exposure-based CBT was associated with improvements in IBS symptoms, IBS-related fear, and quality of life. In studies II and IV, ICBT was more effective than a waiting list and in study V, ICBT was more effective than internet-delivered stress management. Study I also showed that exposure-based CBT leads to improvement in mental health. Conclusions: Exposure-based CBT is effective both in group format and when delivered via internet. Both self-referred and clinical samples of IBS patients improve from the treatment. The effects of exposure-based CBT cannot be explained by non-specific factors such as treatment credibility, expectancy of improvement, and attention from a caregiver. ICBT is a promising new treatment modality that can be made accessible to a large number of IBS patients.