Pain Reprocessing Therapy (PRT) in a Specialist Pain Clinic: A Feasibility Study

Breaking the Pain Cycle: Implementing a Novel Neuroscience-based Behavioral Therapy for Chronic Pain in a Pain Rehabilitation Setting

Long-term pain, which is pain that lasts for more than three months, is a major health problem. It can severely impact a person's physical and mental well-being, quality of life, and ability to work. It also carries high costs for society, mainly due to high rates of sick leave.

For many people with long-term pain, there is no clear injury or disease that fully explains why it hurts. In these cases, the pain is believed to be caused by how the brain and nervous system process pain signals. This is sometimes called "nociplastic pain."

Even though there are many treatments for pain-like medications and therapies-they don't work for everyone, and many people are left without meaningful relief. Because of this, it is important to find and test new ways to treat pain. In this study, the investigators evaluate a relatively new psychological treatment called Pain Reprocessing Therapy (PRT), which has been tested in the US with promising results.

PRT helps individuals with chronic pain to understand and change how they think about their pain by explaining how the brain works. The treatment focuses on teaching the difference between acute (new) pain and long-term pain. It also involves exercises to help people alter emotions related to their pain. A key part of the treatment is a technique where patients practice paying attention to what is happening in their bodies in a safe, relaxed way. The goal is to teach the brain that the pain signals are not a threat. This can help break the vicious cycle of fear, avoiding activities, and worsening pain.

While many people are interested in treatments like PRT, it hasn't yet been tested in specialized care for patients with complex pain. This trial is a pilot study-a smaller, initial investigation to evaluate how well the treatment works in a clinical setting, and to determine if both patients and therapists find it acceptable and practical to use. This will give us important information to help prepare for larger studies in the future.

The main goal of this pilot study is to see if PRT is a practical and accepted treatment in a Swedish pain rehabilitation setting. The investigators also want to look at whether the treatment helps reduce pain, psychological distress, negative thoughts about pain, and the fear of moving. Finally, the investigators will explore how a patient's expectations and thinking skills (such as memory and focus) might affect how well the treatment works, and take physical measurements before and after the treatment to see if the nervous system becomes better at regulating pain.

The overall aim of this project is to conduct a pilot study investigating the feasibility, patient satisfaction, and acceptability of a recently developed psychological treatment for pain: Pain Reprocessing Therapy (PRT). The study will be conducted within a clinical pain rehabilitation setting, where patients frequently present with severe pain, psychiatric comorbidity, and reduced or absent work capacity.

Within the framework of this project, the investigators will evaluate whether PRT can be effectively implemented in a pain rehabilitation context and whether the treatment is perceived as acceptable and feasible by both patients and clinicians. Furthermore, the investigators intend to conduct exploratory analyses to determine if specific clinical subgroups appear more responsive to the intervention.

A secondary aim is to evaluate changes in pain intensity, functional capacity, fear of movement (kinesiophobia), pain catastrophizing, as well as symptoms of anxiety and depression. Although study participants will not be randomized, the results will be compared to a matched reference group drawn from the Swedish Quality Registry for Pain Rehabilitation (SQRP). This reference group, comprising individuals who have undergone standard multimodal pain rehabilitation, is included to provide a contextualizing indication of whether PRT is associated with clinically relevant changes in the outcome measures.

The project is designed as a single-arm pilot study in which all participants will receive PRT. Data collection will occur at baseline, during the intervention, and post-treatment. PRT, which has previously been evaluated primarily in a selected population with chronic back pain and limited comorbidity, aims to modify the patient's interpretation of the cause of their pain and its perceived threat value. By targeting fear-avoidance responses triggered by somatic signals, the ultimate objective of the treatment is to facilitate sustained symptom relief.

Primary Objective:

The primary objective is to investigate whether a 9-week treatment with Pain Reprocessing Therapy (PRT) meets predefined criteria for feasibility and acceptability.

Primary Research Questions:

• Is an adequate recruitment rate achieved among approached patients?
• Does a sufficiently large proportion of the included participants complete the treatment program (retention rate)?
• Does the treatment demonstrate adequate patient satisfaction?
• Are patient attendance and treatment adherence, in terms of completing homework assignments, consistent with predefined benchmarks?
• Do the clinicians demonstrate adequate treatment fidelity to the PRT manual?

Secondary Objective:

The secondary objective is to exploratively investigate whether PRT is associated with changes in predefined clinical outcome measures.

Secondary Research Questions:

• Are there observed changes in self-rated pain experience, quality of life, symptoms of anxiety and depression, fear of movement (kinesiophobia), pain-related catastrophizing, fatigue and sickness behavior?
• How do changes in outcome measures following PRT compare to a matched reference group that has undergone standard multimodal pain rehabilitation?

Exploratory Research Questions:

• Are participants' initial treatment expectations and perceived credibility , as well as their perception of clinician empathy, cognitive functioning and pain sensitivity associated with treatment outcomes?
• How are cognitive function and pain sensitivity affected by the treatment?
• How do participants describe their experiences of the treatment and perceived processes of change in qualitative interviews?

Inclusion Criteria:

• Adults aged 18 years and older.
• Completed medical investigation regarding the pain diagnosis. Primary pain conditions (according to ICD-11) or nociplastic pain, as well as mixed conditions where patients have nociplastic pain combined with nociceptive and/or neuropathic pain (e.g., fibromyalgia, chronic widespread pain, primary chronic back pain).
• Pain duration of at least 3 months.
• Current medication regimen compatible with participating in and benefiting from highly specialized rehabilitation.
• Ability to read, speak, and understand the Swedish language.
• Exclusion Criteria:
• Severe psychiatric conditions (e.g., psychosis, severe depression, and suicidality).
• Current substance abuse (including overuse of prescription medications) or dementia.
• Cancer pain, cauda equina syndrome, or other medical conditions that constitute the primary explanation for the patient's pain.
• Another psychological treatment for pain within the past 3 months.
• Ongoing parallel treatments related to the patient's pain at other clinics, with the exception of ongoing pharmacological treatment.
• Ongoing legal disputes or active claims for disability compensation.