Mindfulness-Based Cognitive Therapy: Efficacy and fMRI-based Response Predictors in a Group of OCD Patients

Obsessive-Compulsive Disorder (OCD) patients have a response rate of 50-60% to exposure and response prevention (ERP) therapy and SSRI antidepressants. Mindfulness-Based Cognitive Therapy (MBCT) consists of training the participant to non-react to negative thoughts and emotions. Applying MBCT to OCD patients may help them behave with equanimity in response to their obsessions, and therefore acknowledge them with the same attention and intention as they admit any other disturbing thought without reacting to it. MBCT has demonstrated effectiveness in major depression, but much less attention has been given to MBCT in OCD. ERP and MBCT, although sharing aspects like exposure, are based on different theoretic and therapeutic factors. EPR is based on a direct anxiety habituation process whereas MBCT trains a holistic manner of becoming familiarized with distressful thoughts and emotions while learning to develop a new relationship to them. Thus, MBCT may decrease anxiety indirectly through a major attention awareness and non-reactivity to thoughts and emotions.

OCD is characterized by altered cortical-striatal-thalamic-cortical (CSTC) circuit and default mode network (DMN) connectivity when performing different tasks and during the resting state. It has been establish that the ventral CSTC circuit is mostly associated with emotional processing, while the dorsolateral aspect of the CSTC circuit is preferentially involved in cognitive processing. In this regard, we hypothesized that clinical amelioration will be accompanied by a re-establishment of functional connectivity within dorsolateral and DMN circuits, which will in turn be associated with improvement of certain neuropsychological processes. CSTC and DMN circuits have also shown to be sensitive to prolonged stress situations. Specifically, childhood trauma has been related to larger brain volumes and it has been associated with different OCD clinical subtypes.

Aims: 1. To assess MBCT effectiveness in treatment non-naive OCD patients. 2. To study cognitive and neuropsychological characteristics that mediate or moderate MBCT response. 3. To examine the changes in cognitive, neuropsychological and neuroimaging patterns associated with an MBCT intervention. 4. To identify a brain biomarker for positive response to MBCT in non-naïve OCD patients. 5. To study cognitive, neuropsychological and early stress expousure mediators or moderators of functional changes in CSTC and DMN patterns in response to MBCT.