Potential treatment mechanisms in a mindfulness-based intervention for people with progressive multiple sclerosis

To explore putative mediators of a mindfulness-based intervention to decrease distress in people with multiple sclerosis (MS) and to explore the patients' perspectives on this intervention.

We used an explanatory mixed methods design incorporating quantitative data from a pilot randomized control trial and a qualitative interview study with people who completed the mindfulness intervention.

People with MS (n = 40) completed standardized measures of distress (outcome), and acceptance, decentring, self-compassion, and self-efficacy (potential mediators). Semi-structured interviews (n = 15) of patients' experiences of the mindfulness intervention were analysed deductively and inductively.

Decentring post-intervention explained 13% of the 3-month change in distress and between 27% and 31% of concurrent changes in distress. Acceptance changed only slightly, and as a result, the indirect effect accounts for only 2% of future distress and between 3% and 11% of concurrent distress. Qualitative data showed that acceptance and self-compassion needed more time to develop, whereas decentring could be implemented readily after being introduced in the sessions. Self-efficacy also had a large mediating effect. Participants in their interviews talked about group dynamics and prior expectations as essential elements that determine their engagement with the course and their level of satisfaction.

Mindfulness interventions for people with a chronic progressive condition may benefit from focusing on helping them to accept daily challenges and teach them to recognize their thoughts and feelings, allowing time for acceptance and self-compassion to develop. Group dynamics also play a fundamental role in the success of the mindfulness interventions. Statement of Contribution What is already known on this subject? Mindfulness courses improve psychological well-being for people with chronic conditions. Mindfulness courses have been successful in improving psychological well-being and symptom management for people with multiple sclerosis but we do not know how these courses work. What does this study add? Decentering and self-efficacy appear to be key mechanisms leading to reduced distress. Acceptance and self-compassion may need more time and practice to develop. Group dynamics and expectations of the mindfulness courses were also important elements of mindfulness.