Patients with Obsessive-Compulsive Disorder (OCD) experience repetitive intrusive thoughts and feel compelled to engage in ritualistic behaviors to reduce anxiety. Treatment with selective serotonin reuptake inhibitors (SSRIs) and cognitive behavioral therapy (CBT) that combines exposure therapy and response prevention can alleviate some symptoms. Yet treatment failure rates remain high (40-60%), and complete remission is rare.

Adjunctive Mindfulness-Based Cognitive Therapy (MBCT) may be beneficial by helping patients observe their obsessive thoughts without becoming emotionally disturbed by them. 

OCD is increasingly characterized as a brain-based disorder involving dysfunctional neural pathways. Functional connectivity studies with OCD patients have shown both hyperconnectivity and hypoconnectivity in regions associated with threat monitoring and executive control. These are areas of the brain where MBCT has been shown to alter functional connectivity in nonclinical populations. 

Serra-Blasco et al. [Psychotherapy and Psychosomatics] conducted a randomized single-blind controlled trial to examine the clinical and neuropsychological effects of adjunctive MBCT in patients with OCD.

The researchers randomly assigned 68 Spanish patients with OCD (average age = 39; 54% female) who had previously undergone SSRI and CBT treatment without remission to either MBCT plus treatment-as-usual or treatment-as-usual alone. MBCT was adapted for patients with OCD and consisted of eight weekly group sessions emphasizing present-moment awareness, challenging irrational beliefs, accepting thoughts and emotions without judgment, promoting self-care, and using mindfulness skills to manage difficult emotions. Treatment-as usual consisted of continued SSRI treatment. 

Participants were assessed before and after treatment using the clinician-rated Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the self-rated Obsessive Compulsive Inventory-Revised (OCI-R). Forty-four of the patients also underwent fMRI brain scanning to assess resting-state functional connectivity at both time points. Psychologists administering the Y-BOCS and conducting the fMRI scans were masked to group assignment. The study retention rate was 67%.

Results showed that the MBCT group had a 32% reduction in Y-BOCS scores, compared to an 8% reduction in the control group (Cohen’s d=1.05). Clinician-rated remission (≥50% improvement) was achieved by 25% of the MBCT group and 4% of the control group. No group differences were detected on the self-reported OCI-R, and MBCT did not produce identifiable changes in resting-state functional connectivity compared to controls. 

However, baseline functional connectivity patterns predicted treatment response. Greater connectivity between the cuneus and ventral default mode network predicted poorer outcomes, whereas lower connectivity between the lower left dorsomedial prefrontal cortex within the  salience network predicted greater improvement. Reduced connectivity in the right pallidum and thalamus also predicted greater clinical improvement.

The study demonstrates that adjunctive MBCT can increase clinician-rated symptom improvement and remission rates in OCD compared to usual care with SSRIs. Although MBCT did not alter brain functional connectivity after treatment, baseline brain networks predicted clinical outcomes. Patients with lower baseline OCD severity were less likely to complete self-report measures, and this, combined with the small sample size, may have reduced power to detect self-reported changes. Because all participants were taking SSRIs and had prior CBT, these treatments may have already influenced neural connectivity, potentially obscuring MBCT-related effects.

Reference:

Serra-Blasco, M., Miquel-Giner, N., Vicent-Gil, M., ... López-Solà, C. (2025). Clinical and Neuroimaging Effects of Mindfulness-Based Cognitive Therapy for Symptomatic OCD Patients after First-Line Treatments: A Randomised Controlled Trial. Psychotherapy and Psychosomatics. 

Link to study