An evaluation of the acceptability and efficacy of remote treatments for obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a common, chronic, and disabling anxiety disorder. Although effective psychological treatments exist they are not widely available, and most people seeking treatment for OCD do not receive an evidence-based intervention. The remote delivery of psychological treatments represents one strategy with considerable potential for improving access to treatments for people with OCD, particularly for those who are geographically isolated. However, only a small number of studies have investigated the acceptability and efficacy of remote treatments for people with OCD. The aims of this thesis were to contribute to the literature on remote treatment of OCD by exploring the following questions: 1) Are remote treatments acceptable to people with OCD (Study I)? 2) Is internetadministered cognitive and behavioural treatment (iCBT) for OCD efficacious (Study II)? 3) Is iCBT as effective as bibliotherapy-administered cognitive and behavioural treatment (Study III)? 4) How much therapist time is required in remote treatments to obtain positive outcomes (Study III)? 5) Do demographic and clinical characteristics predict outcome of remote treatment (Study IV)? -- The results of Study I, an online survey of people with elevated symptoms of OCD, indicated that internet-administered treatment was acceptable and that people seeking online treatment were not significantly different from those seeking face-to-face treatment or from those with OCD in a national epidemiological survey. The results of Study II, a pilot study exploring the efficacy of iCBT for OCD using an open-trial design, indicated iCBT was efficacious, with large effect sizes observed from pre-treatment to post-treatment, which were maintained at follow-up. The results of Study III, a three-parallel group randomised controlled trial comparing iCBT vs. bibliotherapy vs. waitlist control, indicated both iCBT and bibliotherapy were superior to waitlist, with no significant differences between treatment groups, although small sample size limits the generalisability of these results. Study III also revealed that large effect sizes can be obtained in iCBT treatment when contact is limited to once a week, although greater effects were found from more frequent contact. Study IV, which involved an analysis of the data from Study II and III failed to identify any reliable predictors of treatment outcome. -- In summary, these studies indicate that remote treatment of OCD, delivered as either iCBT or bibliotherapy, is both efficacious and acceptable to people with OCD. Replication and extension of these findings by other research teams is required. The results of the studies in this thesis provide further evidence to indicate that remote treatments have considerable potential in improving access to acceptable, evidence-based interventions for individuals with OCD.