Getting close with discomfort : exposure therapy for fibromyalgia

Sammanfattning: Background: Fibromyalgia (FM) is a common and debilitating disorder for which there are currently no treatments available that are satisfyingly effective. Cognitive behavior therapy (CBT) might be a promising treatment option, but most CBT studies—evaluating various multi-component protocols—have rendered mixed results. Exposure therapy has shown some promise in treating other chronic pain conditions, but has not been evaluated specifically for patients with FM. The general aim of this PhD project was to develop and evaluate an exposure therapy protocol for FM. More specifically, the aims were to investigate: • The acceptability and efficacy of internet-delivered exposure therapy for FM (Study I and II). • The cost-effectiveness of the treatment (Study III). • Potential mediators of treatment effect (Study IV). Methods: Acceptability, preliminary efficacy and health economic effects of the treatment was investigated in an open pilot study (Study I). The efficacy of the treatment was evaluated in a randomized controlled trial, where participants were randomized to either internet-delivered exposure therapy (iExp) or a waitlist control (WLC) (Study II). Participants were individuals 18-65 who had received a FM diagnosis from a physician and who self-referred to participate in the studies. Primary outcome was FM symptoms, and secondary outcomes included fatigue, disability, quality of life, anxiety, depression, insomnia and psychological inflexibility. The treatment consisted of 10 weeks of therapist-supported exposure therapy delivered on an online platform. The cost-effectiveness of the treatment was investigated from both a societal perspective and a healthcare unit perspective using data from the randomized trial (Study III). To investigate potential mediators of treatment effect, a mediational analysis was conducted using data from the randomized trial with weekly measurements of three potential mediators (FM-related avoidance behavior, mindful non-reactivity and FM-related worry) and treatment outcome (FM symptoms) (Study IV). Results: Therapist-supported exposure therapy rendered acceptable adherence and treatment completion, with over 70% of participants initiating work with exposure in both Study I and II. Participants receiving iExp had significantly lower FM symptoms at post-treatment, compared to pre-treatment (Study I) and compared to the WLC (Study II), respectively. Moderate within-group (Study I) to large between-group (Study II) effect sizes favoring iExp was observed on the primary outcome, and significant improvements were also observed on all secondary outcomes (Study I-II). All improvements were maintained at the 6- (Study I-II) and 12- (Study II) month follow-up. iExp was highly cost-effective compared to no treatment, with each successful treatment incurring a large societal cost saving (Study III). A reduction in avoidance behavior mediated a reduction in FM symptoms for participants receiving iExp compared to participants in the waitlist group (Study IV). Conclusion: Overall, the studies in this PhD project point to that iExp is an acceptable, effective and cost-effective treatment for FM compared to waitlist control, and that targeting avoidance behavior may be important in exposure therapy for FM. Future studies are needed that compares iExp against an active treatment control, and will benefit if including competing mediators of a different treatment paradigm.