Enhancing the Acceptability of Psychological Treatments for Obsessive-compulsive Disorder

Effective treatments for obsessive-compulsive disorder (OCD) usually emphasize a behavioural approach called Exposure and Response Prevention (ERP). In this treatment, patients are encouraged to face their fears repeatedly and for extended periods of time, with the help and support of a caring therapist. Although this is an approach that has been shown to work, many patients find the treatment to be difficult; some even refuse the treatment, or drop out before improvements are seen. The investigators have been working to develop an alternate approach which is just as effective as ERP, but which the investigators think will be much more acceptable to those who seek help for their OCD. This study will compare the traditional behavioural approach, with the newer cognitively-based approach. The investigators expect that the two treatments will both reduce the symptoms and distress of people with OCD, but that this newer cognitive therapy will have fewer people who refuse or drop out of the treatment, and will be rated as more acceptable. This research will have important implications not only for those struggling with OCD, but also for other anxiety-related problems where behavioural approaches are typically recommended, including posttraumatic stress disorder, social anxiety disorder, and other problems.

Obsessive-Compulsive Disorder (OCD) is a serious and often severe mental disorder and one of the leading causes of disability worldwide. Effective psychological interventions for OCD exist, but the prevailing option (Exposure and Response Prevention; ERP) has changed very little since it was established in the 1960's; moreover, it is associated with unacceptably high numbers of individuals who drop out from, or refuse the treatment altogether. This is largely because ERP is a difficult treatment, wherein individuals face their fears with increasing difficulty over time. Just as with the development from early chemotherapy and HIV agents, which were effective, but associated with serious and often severe side effects, it is now time to enhance the acceptability of psychological treatments for OCD.

A novel cognitive therapy (CT) approach is likely to be just as effective as ERP, but markedly more acceptable to those who need it. Although CT for OCD is as effective as ERP, previously tested CTs have failed to incorporate recent experimental research, novel cognitive targets or enhancements to acceptability. Indeed, the investigators recent work on treatment acceptability promises to increase the number of individuals who can fully and successfully engage with the treatment.

The purpose of this research is to enhance the acceptability of cognitive-behavioural treatments for OCD; the investigators aim to accomplish this via a randomized controlled trial comparing traditional ERP against the investigators' novel CT approach. Although the investigators expect both treatments to be effective, the primary hypothesis is that CT will be significantly more acceptable to participants than ERP; this will be assessed by the relative numbers of treatment refusers and dropouts, as well as by participant ratings of treatment acceptability.

Eligibility Criteria:
Inclusion Criteria:

* Diagnosis of OCD
* Ability to read, write, and communicate in English

Exclusion Criteria:

* Psychosis
* Diagnosis of bipolar disorder (I or II)
* Current suicidal ideation/intent
* Current substance abuse
* If participants are on medication they must be on a stable dose (i.e. have maintained a consistent dose for at least three months) and agree not to change their medication regimen for the duration of the study