[Mindfulness-based interventions in obsessive-compulsive disorder: Mechanisms of action and presentation of a pilot study].

Obsessive-compulsive disorder (OCD) is a frequent and severe disease, potentially inducing a major impairment for the patient and burden for their family. Recent research in psychiatry and neuroscience have led to better comprehension of the disease's mechanisms and helped to improve its treatment. However, a large proportion of patients have refractory symptoms, including for traditional cognitive and behavioral therapy by exposure and response prevention (ERP), leading clinicians to look for new treatments. Mindfulness-based interventions (MBI) are a new type of approach, initially based on Buddhist meditation, which aims to provide better consciousness of the present moment. It has been successfully developed in some psychiatric diseases and other general medical conditions such as chronic pain. The two main programs using mindfulness meditation, Mindfulness-based stress reduction (MBSR) and Mindfulness-based cognitive therapy (MBCT), have shown effectiveness for the reduction of depressive and anxiety symptoms and relapses of depressive episodes in unipolar depression. It has no side effects and is well tolerated by patients. Its action relies on the specific correction of cognitive deficits in attention, emotion regulation and executive functions which are shared by OCD, GAD and depression. For OCD, we make the hypothesis that Mindfulness-Based Interventions could reduce the cognitive bias specifically existing in this pathology, such as dysfunctional beliefs, and therefore improve the symptoms. This article first reviews the existing literature on clinical trials involving Mindfulness-Based Interventions in OCD which comprises a small number of clinical studies based on very different types of protocols. At this time, and due to the lack of gold-standard studies with a large number of patients, no proof of the efficiency of mindfulness-based interventions in OCD has been shown. In a second section, following our hypothesis on the mechanisms of specific and non-specific action of this therapy in OCD, we propose a cognitive model of mindfulness-based therapy action in OCD involving the correction of OCD's cognitive bias. In this model, mindfulness-based therapy is supposed to treat specifically the cognitive aspects of the disease, while ERP is focused on its behavioral part. Then we present a clinical study aiming to prove the feasibility and the interest of the use of mindfulness in OCD, carried out in two different clinical centers. One of them used MBCT while the second used MBSR. Its results show the feasibility of mindfulness-based therapy in OCD patients and tend to prove that it could be more effective in young patients suffering from less severe forms of OCD. In parallel, attention tests and fMRI scans were done at the beginning and at the end of the therapy. Their results will be published separately. We also discuss the putative role of a specific form of MBCT adapted for OCD, specifically for its benefits in psychoeducation, which could reduce the dysfunctional beliefs present in OCD patients. Finally, we propose a therapeutic strategy in which the MBCT could complement the classical ERP therapy, as a "maintenance" treatment, aiming to extend the relapse of OCD symptoms. This article is a step further in the use of mindfulness-based therapy for OCD which could be added to the existing treatments reducing the patient's symptoms and improving their quality of life.