“Effect of Pain Reprocessing Therapy vs Placebo and Usual Care for Patients With Chronic Back Pain: A Randomized Clinical Trial”, 2021-09-29 ():
Question: Can a psychological treatment based on the reappraisal of primary chronic back pain as due to non-dangerous central nervous system processes provide substantial and durable pain relief?
Results: In this randomized clinical trial, 1⁄2 participants (66%) randomized to 4 weeks of pain reprocessing therapy were pain-free or nearly pain-free at post-treatment, compared with 1⁄2 participants (20%) randomized to placebo and 1⁄2 participants (10%) randomized to usual care, with gains largely maintained through 1-year follow-up. Treatment effects on pain were mediated by reduced beliefs that pain indicates tissue damage, and longitudinal functional magnetic resonance imaging showed reduced prefrontal responses to evoked back pain and increased resting prefrontal-somatosensory connectivity in patients randomized to treatment relative to patients randomized to placebo or usual care.
Meaning: Psychological treatment focused on changing beliefs about the causes and threat value of primary chronic back pain may provide substantial and durable pain relief.
Importance: Chronic back pain (CBP) is a leading cause of disability, and treatment is often ineffective. ~85% of cases are primary CBP, for which peripheral etiology cannot be identified, and maintenance factors include fear, avoidance, and beliefs that pain indicates injury.
Objective: To test whether a psychological treatment (pain reprocessing therapy [PRT]) aiming to shift patients’ beliefs about the causes and threat value of pain provides substantial and durable pain relief from primary CBP and to investigate treatment mechanisms…We developed pain reprocessing therapy (PRT) based on this understanding of primary chronic pain. Leading psychological interventions for pain typically present the causes of pain as multifaceted and aim primarily to improve functioning and secondarily to reduce pain. PRT emphasizes that the brain actively constructs primary chronic pain in the absence of tissue damage and that reappraising the causes and threat value of pain can reduce or eliminate it.
Design, Setting, & Participants: This randomized clinical trial with longitudinal functional magnetic resonance imaging (fMRI) and 1-year follow-up assessment was conducted in a university research setting from November 2017 to August 2018, with 1-year follow-up completed by November 2019. Clinical and fMRI data were analyzed from January 2019 to August 2020. The study compared PRT with an open-label placebo treatment and with usual care in a community sample.
Interventions: Participants randomized to PRT participated in 1 telehealth session with a physician and 8 psychological treatment sessions over 4 weeks. Treatment aimed to help patients reconceptualize their pain as due to non-dangerous brain activity rather than peripheral tissue injury, using a combination of cognitive, somatic, and exposure-based techniques. Participants randomized to placebo received an open-label subcutaneous saline injection in the back; participants randomized to usual care continued their routine, ongoing care.
Main Outcomes & Measures: One-week mean back pain intensity score (0 to 10) at post-treatment, pain beliefs, and fMRI measures of evoked pain and resting connectivity.
Results: At baseline, 151 adults (54% female; mean [SD] age, 41.1 [15.6] years) reported mean (SD) pain of low to moderate severity (mean [SD] pain intensity, 4.10 [1.26] of 10; mean [SD] disability, 23.34 [10.12] of 100) and mean (SD) pain duration of 10.0 (8.9) years. Large group differences in pain were observed at post-treatment, with a mean (SD) pain score of 1.18 (1.24) in the PRT group, 2.84 (1.64) in the placebo group, and 3.13 (1.45) in the usual care group. Hedges g was −1.14 for PRT vs placebo and −1.74 for PRT vs usual care (p < 0.001). Of 151 total participants, 1⁄2 participants (66%) randomized to PRT were pain-free or nearly pain-free at post-treatment (reporting a pain intensity score of 0 or 1⁄2), compared with 1⁄2 participants (20%) randomized to placebo and 1⁄2 participants (10%) randomized to usual care. Treatment effects were maintained at 1-year follow-up, with a mean (SD) pain score of 1.51 (1.59) in the PRT group, 2.79 (1.78) in the placebo group, and 3.00 (1.77) in the usual care group. Hedges g was −0.70 for PRT vs placebo (p = 0.001) and −1.05 for PRT vs usual care (p < 0.001) at 1-year follow-up. Longitudinal fMRI showed (1) reduced responses to evoked back pain in the anterior midcingulate and the anterior prefrontal cortex for PRT vs placebo; (2) reduced responses in the anterior insula for PRT vs usual care; (3) increased resting connectivity from the anterior prefrontal cortex and the anterior insula to the primary somatosensory cortex for PRT vs both control groups; and (4) increased connectivity from the anterior midcingulate to the precuneus for PRT vs usual care.
Conclusions & Relevance: Psychological treatment centered on changing patients’ beliefs about the causes and threat value of pain may provide substantial and durable pain relief for people with CBP.
Trial Registration: ClinicalTrials.gov Identifier: NCT03294148.