Shared and Differential Psychological Processes Associated With Treatment Response in Mindful Self-Compassion and Cognitive-Behavioural Therapy for Chronic Pain: An Exploratory Secondary Analysis of a Randomized Controlled Trial.

BACKGROUND

Psychological treatments for chronic pain are effective, but the processes associated with therapeutic change, and whether these are shared across treatments or treatment-specific, remain unclear. This exploratory secondary analysis examined whether changes in pain acceptance, pain catastrophizing facets and self-compassion were associated with clinical outcomes in Mindful Self-Compassion (MSC) versus Cognitive-Behavioural Therapy (CBT).

METHODS

Data were drawn from a randomized trial comparing MSC (n = 61) and CBT (n = 59) in adults with chronic pain and elevated emotional distress. Processes and outcomes were assessed at baseline and post-treatment. Single and theoretically ordered multiple-mediator models examined whether changes in pain acceptance, rumination, magnification, helplessness and self-compassion were associated with changes in anxiety, depression, quality of life, pain interference and pain intensity.

RESULTS

Compared with CBT, MSC produced larger increases in pain acceptance and reductions in helplessness. These processes statistically accounted for improvements in self-compassion, depression, mental quality of life and pain interference; acceptance additionally accounted for reduced pain intensity, and helplessness for reduced anxiety. Rumination and magnification predicted improvements across treatments but did not explain between-group differences. Multiple-mediator models indicated that acceptance/self-compassion and helplessness/self-compassion pathways favoured MSC for depression, anxiety and mental quality of life, explaining up to 51% of change. No mediator accounted for physical quality of life.

CONCLUSIONS

MSC and CBT appeared to engage overlapping processes, with differential associations mainly involving pain acceptance and helplessness. Acceptance may be more relevant to functional and pain-related outcomes, whereas helplessness/self-compassion pathways may be more relevant to emotional recovery.

SIGNIFICANCE STATEMENT: This study identifies pain acceptance and reduced helplessness as candidate processes associated with treatment response in MSC and CBT, with acceptance more closely linked to pain-related and functional change and helplessness to emotional outcomes. These findings support more precise, process-based psychological treatment for chronic pain.