Pain reprocessing therapy, five years on.

What is pain reprocessing therapy?

Pain reprocessing therapy, or PRT, is a psychological treatment for chronic pain that has no clear ongoing tissue cause. Its premise is that for many people with primary chronic back pain, pain is maintained by the brain's learned interpretation of signals as dangerous, along with fear, avoidance and the belief that pain means injury. The trial authors noted that roughly 85 percent of chronic back pain is primary, meaning no peripheral cause can be identified.

PRT aims to help people reconceptualize their pain as the product of non-dangerous brain activity rather than tissue damage. The trial describes it as a combination of cognitive, somatic and exposure-based techniques: education about how the brain generates pain, gathering personal evidence that pain is not caused by damage, somatic tracking (attending to pain sensations with curiosity and a sense of safety), exposure to feared movements, and work on the emotions and stressors that amplify threat. Our guide to PRT covers the method in detail.

What did the original Boulder trial find?

The study, led by Yoni Ashar and Tor Wager with Alan Gordon, Howard Schubiner and Mark Lumley among the collaborators, enrolled 151 adults with primary chronic back pain from the community and treated them in a university research setting. Baseline pain averaged about 4 out of 10, and people had lived with it for about 10 years. Participants were randomized to one of three groups: PRT (one telehealth session with a physician plus eight psychological sessions over four weeks), an open-label placebo (a saline injection in the back, with participants told it was a placebo), or usual care.

The standardized effect sizes were large: Hedges g of -1.14 versus placebo and -1.74 versus usual care. The trial also included brain imaging. After PRT, people showed reduced responses to evoked back pain in regions involved in pain and its meaning, including the anterior midcingulate cortex, anterior prefrontal cortex and anterior insula, along with changes in resting connectivity. Those findings fit the idea that PRT changes how the brain appraises pain, though imaging alone cannot prove the mechanism.

What did the five-year follow-up show?

In 2025 the team reported on 113 of the original 151 participants, 75 percent, five years after treatment. PRT participants still reported lower pain than both comparison groups: an adjusted average of 1.93, versus 3.19 for placebo and 2.60 for usual care, standardized differences of -0.83 and -0.62. About 55 percent of the PRT group were nearly or completely pain-free, compared with 26 percent in the placebo group and 36 percent in usual care.

PRT participants also showed lasting improvements in pain interference, depression, anger, the belief that pain reflects harm, and the attribution of pain to mind and brain processes. There were no significant five-year differences in sleep, anxiety, positive mood, catastrophizing or perceived control over pain.

What are the limits of these results?

The results are striking and they deserve careful reading.

• One site, one kind of patient. The trial ran at a single university center with a relatively educated, community-recruited sample whose pain was mostly mild to moderate. Whether the same effects appear in people with severe pain, or in ordinary clinics, is not yet known.
• No blinding. People knew which treatment they received. Psychological treatments cannot be blinded the way pills can, and expectation is part of any such result.
• A subset at five years. A quarter of participants were not followed up, which introduces uncertainty about the long-term figures.
• Disclosed interests. Several authors reported relationships with organizations that train clinicians in PRT or deliver related programs. That does not invalidate the findings; it makes independent replication especially valuable.

Replication in larger, more diverse samples and in other conditions is the next step. Early work has begun, including a feasibility pilot in fibromyalgia (Sturgeon et al., 2025) and a migraine case series (Fishbein et al., 2025). These are preliminary and not comparable to a full randomized trial.

What does this mean for someone with chronic back pain?

The trial showed that a short psychological treatment focused on changing beliefs about the cause and danger of pain produced large and durable reductions in pain for many people with primary chronic back pain. It strengthens the case that, for some forms of chronic pain, the brain's appraisal of threat is a treatable target. It also reminds us that one trial is a strong start, not the final word.

PRT is for pain that persists after serious causes have been ruled out, which is why it begins with a medical evaluation. Approaches like it inform how Karuna thinks about pain reprocessing, with VR embodiment and one-on-one coaching added to the same core idea. See how it works.