The effects of mindfulness-based cognitive therapy in patients with bipolar disorder: A controlled functional MRI investigation

Abstract

Background

Preliminary research findings have shown that mindfulness-based cognitive therapy improves anxiety and depressive symptoms in bipolar disorder. In this study, we further investigated the effects of MBCT in bipolar disorder, in a controlled fMRI study.

Method

Twenty three patients with bipolar disorder underwent neuropsychological testing and functional MRI. Sixteen of these patients were tested before and after an eight-week MBCT intervention, and seven were wait listed for training and tested at the same intervals. The results were compared with 10 healthy controls.

Results

Prior to MBCT, bipolar patients reported significantly higher levels of anxiety and symptoms of stress, scored significantly lower on a test of working memory, and showed significant BOLD signal decrease in the medial PFC during a mindfulness task, compared to healthy controls. Following MBCT, there were significant improvements in the bipolar treatment group, in measures of mindfulness, anxiety and emotion regulation, and in tests of working memory, spatial memory and verbal fluency compared to the bipolar wait list group. BOLD signal increases were noted in the medial PFC and posterior parietal lobe, in a repeat mindfulness task. A region of interest analysis revealed strong correlation between signal changes in medial PFC and increases in mindfulness.

Limitations

The small control group is a limitation in the study.

Conclusion

These data suggest that MBCT improves mindfulness and emotion regulation and reduces anxiety in bipolar disorder, corresponding to increased activations in the medial PFC, a region associated with cognitive flexibility and previously proposed as a key area of pathophysiology in the disorder.

Introduction

Bipolar disorder is a chronic disorder of mood affecting 2% of the population (Kessler et al., 2005). The condition is characterized by cyclical states of mania and depression. Manic states are marked by persistently elevated mood and may include high levels of irritability, while depression states are periods of persistent feelings of sadness, futility and worthlessness (DSM-IV-TR). Bipolar disorder is characterized by emotional dysregulation and patients therefore demonstrate impairments in emotional control and executive functioning, even during euthymic states (Green et al., 2007, Phillips et al., 2008).

Pharmacological management is considered the treatment of choice for bipolar disorder and there is some evidence that cognitive-behavioural therapy (CBT), group psycho-education and possibly family therapy may be beneficial as adjuncts to pharmacological maintenance treatments for the prevention of relapse in stable patients (Beyon et al., 2008, Scott et al., 2007, Vieta and Colom, 2004). CBT in bipolar disorder focuses on recognizing early promodal symptoms and using behavioural regulation strategies to prevent relapse. The related technique of noticing and observing mood fluctuations and changes in symptomatology, and responding in a regulated way to these signals, is one of the primary skills taught in mindfulness-based interventions. Acquiring mindfulness through training, which focuses on increasing awareness and reevaluating mental processes, has been shown to increase positive affect and reduce cognitive vulnerability to stress and emotional distress in clinical and non-clinical populations (Grossman et al., 2004). Mindfulness-based cognitive therapy (MBCT) combines mindfulness training and CBT techniques, and has been reported to reduce relapse in major depression (Teasdale et al., 1995).

The effects of mindfulness training in bipolar disorder patients have yet to be fully explored. A preliminary evaluation of the effects of MBCT in bipolar disorder has been conducted with a specific focus on between-episode anxiety and depressive symptoms (Williams et al., 2008). Using data from a randomized wait list trail of MBCT for people with bipolar disorder in remission, these authors reported improved anxiety and depressive symptoms following MBCT. Reductions in anxiety, but not in relapse rate, were reported in a controlled study of bipolar patients 12 months after MBCT (Perich et al., 2012). Improvements in cognitive functioning in bipolar patients have also been reported following MBCT (Stange et al., 2011). Deficits in early information processing and emotional dysregulation, reported by EEG and HRV measures, were reportedly attenuated following MBCT (Howells et al., 2011). We are not aware of reports of neuroimaging studies of the effects of MBCT in people with bipolar disorder.

Although a diverse range of activation patterns have been reported in functional neuroimaging studies of mindfulness meditation, several studies report signal increases in the dorsolateral PFC and the anterior cingulate cortex (Baerentsen, 2001; Creswell et al., 2007; Farb et al., 2007, Lazar et al., 2005, Ritskes et al., 2003). In novice meditators the early stages of mindfulness meditation are associated with activations in attentional control networks including the medial PFC, anterior and posterior cingulate cortices (Chiesa and Serretti, 2010, Hölzel, 2007). Informed by the findings of these studies, we expected to find comparable activation patterns in midline cortical regions, during a mindfulness meditation task, in healthy participants with altered activation patterns in bipolar patients. We hypothesized improvements in cognitive function, clinical measures of mindfulness, and mood and anxiety symptoms, and increased activations in midline cortical regions in bipolar disorder patients, following an eight-week MBCT intervention.