Mindfulness-Based Cancer Recovery (MBCR) versus Supportive Expressive Group Therapy (SET) for distressed breast cancer survivors: evaluating mindfulness and social support as mediators.

Despite growing evidence in support of mindfulness as an underlying mechanism of mindfulness-based interventions (MBIs), it has been suggested that nonspecific therapeutic factors, such as the experience of social support, may contribute to the positive effects of MBIs. In the present study, we examined whether change in mindfulness and/or social support mediated the effect of Mindfulness-Based Cancer Recovery (MBCR) compared to another active intervention (i.e. Supportive Expressive Group Therapy (SET)), on change in mood disturbance, stress symptoms and quality of life. A secondary analysis was conducted of a multi-site randomized clinical trial investigating the impacts of MBCR and SET on distressed breast cancer survivors (MINDSET). We applied the causal steps approach with bootstrapping to test mediation, using pre- and post-intervention questionnaire data of the participants who were randomised to MBCR (n = 69) or SET (n = 70). MBCR participants improved significantly more on mood disturbance, stress symptoms and social support, but not on quality of life or mindfulness, compared to SET participants. Increased social support partially mediated the impact of MBCR versus SET on mood disturbance and stress symptoms. Because no group differences on mindfulness and quality of life were observed, no mediation analyses were performed on these variables. Findings showed that increased social support was related to more improvement in mood and stress after MBCR compared to support groups, whereas changes in mindfulness were not. This suggests a more important role for social support in enhancing outcomes in MBCR than previously thought.

Randomized-controlled trial of mindfulness-based cancer recovery versus supportive expressive group therapy among distressed breast cancer survivors (MINDSET): long-term follow-up results.

BACKGROUND: Mindfulness-based cancer recovery (MBCR) and supportive expressive group therapy (SET) are two well-validated psychosocial interventions, but they have not been directly compared, and little is known about long-term outcomes. This comparative effectiveness study measured the effects of these two interventions immediately following the groups and for 1 year thereafter in distressed breast cancer survivors. METHODS: Two hundred fifty-two distressed Stage I-III breast cancer survivors were randomized into either MBCR or SET. Women completed questionnaires addressing mood, stress symptoms, quality of life, social support, spirituality and post-traumatic growth before and after the interventions, and 6 and 12 months later. RESULTS: Immediately following the intervention, women in MBCR reported greater reduction in mood disturbance (primarily fatigue, anxiety and confusion) and stress symptoms including tension, sympathetic arousal and cognitive symptoms than those in SET. They also reported increased emotional and functional quality of life, emotional, affective and positive social support, spirituality (feelings of peace and meaning in life) and post-traumatic growth (appreciation for life and ability to see new possibilities) relative to those in SET, who also improved to a lesser degree on many outcomes. Effect sizes of the time × group interactions were small to medium, and most benefits were maintained over 12 months of follow-up. CONCLUSIONS: This study is the first and largest to demonstrate sustained benefits of MBCR in distressed breast cancer survivors relative to an active control. MBCR was superior to SET for improving psychological well-being with lasting benefits over 1 year, suggesting these women gained long-lasting and efficacious tools to cope with cancer. TRIAL REGISTRATION: Registered on clinicaltrials.gov number NCT00390169, October 2006. Copyright © 2016 John Wiley & Sons, Ltd.

Randomized controlled trial of Mindfulness-based cancer recovery versus supportive expressive group therapy for distressed survivors of breast cancer.

PURPOSE: To compare the efficacy of the following two empirically supported group interventions to help distressed survivors of breast cancer cope: mindfulness-based cancer recovery (MBCR) and supportive-expressive group therapy (SET). PATIENTS AND METHODS: This multisite, randomized controlled trial assigned 271 distressed survivors of stage I to III breast cancer to MBCR, SET, or a 1-day stress management control condition. MBCR focused on training in mindfulness meditation and gentle yoga, whereas SET focused on emotional expression and group support. Both intervention groups included 18 hours of professional contact. Measures were collected at baseline and after intervention by assessors blind to study condition. Primary outcome measures were mood and diurnal salivary cortisol slopes. Secondary outcomes were stress symptoms, quality of life, and social support. RESULTS: Using linear mixed-effects models, in intent-to-treat analyses, cortisol slopes were maintained over time in both SET (P = .002) and MBCR (P = .011) groups relative to the control group, whose cortisol slopes became flatter. Women in MBCR improved more over time on stress symptoms compared with women in both the SET (P = .009) and control (P = .024) groups. Per-protocol analyses showed greater improvements in the MBCR group in quality of life compared with the control group (P = .005) and in social support compared with the SET group (P = .012). CONCLUSION: In the largest trial to date, MBCR was superior for improving stress levels, quality of life and social support [CORRECTED] for distressed survivors of breast cancer. Both SET and MBCR also resulted in more normative diurnal cortisol profiles than the control condition. The clinical implications of this finding require further investigation.