Neuroimaging Supports Beneficial Effect of Cognitive Behavioral Therapy on Pain Catastrophizing in Fibromyalgia
Takeaways
- This randomized, controlled trial evaluated the effects of eight weeks of cognitive behavioral therapy (CBT) on pain interference and pain catastrophizing in patients with fibromyalgia and the brain circuitry underlying pain catastrophizing.
- CBT was superior to a matched education intervention in reducing pain interference and the functional impact of fibromyalgia.
- Within the CBT group, improvements were at least partly attributable to reductions in pain catastrophizing.
- After CBT, functional MRI showed changes in connectivity between the default mode network, salience network, and somatomotor network, which may reflect CBT-induced shifts in somatic self-awareness, pain, and emotional processing.
- These results emphasize the important role of pain catastrophizing in fibromyalgia and the need to target it with psychotherapy.
A 2020 Cochrane systematic review concluded cognitive behavioral therapy (CBT) has a beneficial effect on chronic pain, including fibromyalgia. In particular, CBT was judged effective in improving mood and pain-related catastrophizing.
A new randomized trial provides further evidence that CBT reduces pain catastrophizing in patients with fibromyalgia, and accompanying neuroimaging data show that CBT reduces connectivity between regions of the brain associated with somatic self-awareness, pain, and emotional processing.
Jeungchan Lee, PhD, an instructor in Physical Medicine and Rehabilitation at Spaulding Rehabilitation, Vitaly Napadow, PhD, of Spaulding Rehabilitation and director of the Center for Integrative Pain NeuroImaging at the Massachusetts General Hospital Martinos Center for Biomedical Imaging, and colleagues report in Arthritis & Rheumatology.
Methods
Between 2017 and 2022, the team randomly assigned 98 women, ages 18 to 75, to receive CBT with active skills training (n=64) or education about fibromyalgia and chronic pain (n=34). Both interventions involved individual 60- to 75-minute weekly visits with a mental health professional for eight weeks.
Before and after the intervention, patients underwent functional MRI and completed the Brief Pain Inventory (BPI), the Fibromyalgia Impact Questionnaire Revised (FIQR), and the Pain Catastrophizing Scale (PCS).
During a novel fMRI catastrophizing task devised by this group, the participants viewed six statements from the PCS and six control neutral statements. They were asked to reflect on their engagement in such thoughts during episodes of fibromyalgia pain.
Clinical Results
CBT improved most clinical outcomes more than education did:
- BPI pain interference: Change in CBT group, −1.3 point vs. change in education group, −0.2 point (P=0.03)
- BPI pain severity: −0.6 vs. 0 (P=0.34)
- FIQR: −8.1 vs. −1.5 (P=0.05)
- PCS: −8.7 vs. −4.6 (P=0.04)
Change in PCS scores significantly mediated the effects of group on changes in BPI pain interference, BPI pain severity and FIQR scores.
Neuroimaging Results
At baseline, pain catastrophizing activated the ventral posterior cingulate cortex (vPCC), a key node of the default mode network (DMN), which is critically important in self-referential cognitive processes.
At baseline, engaging in the pain catastrophizing fMRI task increased connectivity between the vPCC and brain regions of the salience network, which regulates dynamic switching between interoceptive and exteroceptive cognitive models.
After CBT, patients demonstrated decreased vPCC connectivity to the salience network and the somatomotor network, which processes physical stimuli and motor responses.
Clinical and Research Implications
These results emphasize the importance of targeting pain catastrophizing with psychotherapy. Catastrophizing might even emerge as an important phenotyping variable that could guide the selection of optimal treatments.
The neuroimaging data suggest connectivity between the default mode, salience, and somatosensory networks may be a valuable biomarker of catastrophizing-related cognitive and affective processes.