Mindfulness-based cognitive therapy versus psychoeducational intervention in bipolar outpatients with sub-threshold depressive symptoms: a randomized controlled trial

Background: The presence of depressive subsyndromal symptoms (SS) in bipolar disorder (BD) increases the risk of affective relapse and worsens social, cognitive functioning, and quality of life. Nonetheless, there are limited data on how to optimize the treatment of subthreshold depressive symptoms in BD. Mindfulness-Based Cognitive Therapy (MBCT) is a psychotherapeutic intervention that has been shown effective in unipolar depression. The assessment of its clinical effectiveness and its impact on biomarkers in bipolar disorder patients with subsyndromal depressive symptoms and psychopharmacological treatment is needed. Methods/design: A randomized, multicenter, prospective, versus active comparator, evaluator-blinded clinical trial is proposed. Patients with BD and subclinical or mild depressive symptoms will be randomly allocated to: 1) MBCT added to psychopharmacological treatment; 2) a brief structured group psychoeducational intervention added to psychopharmacological treatment; 3) standard clinical management, including psychopharmacological treatment. Assessments will be conducted at screening, baseline, post-intervention (8 weeks) and 4 month follow-up post-intervention. The aim is to compare MBCT intervention versus a brief structured group psychoeducation. Our hypothesis is that MBCT will be more effective in reducing the subsyndromal depressive symptoms and will improve cognitive performance to a higher degree than the psychoeducational treatment. It is also hypothesized that a significant increase of BDNF levels will be found after the MBCT intervention. Discussion: This is the first randomized controlled trial to evaluate the effects of MBCT compared to an active control group on depressive subthreshold depressive symptoms in patients with bipolar disorder.