What Is Chronic Pain?
Chronic pain is pain that persists longer than the expected time for tissues to heal, typically defined as more than three months. It affects roughly one in five Canadian adults and is one of the leading causes of disability worldwide.
Contemporary pain science divides chronic pain into two ICD-11 categories:
- Chronic primary pain: pain is the disease itself, with no clear ongoing tissue damage. Examples include fibromyalgia, chronic primary low back pain, chronic primary headache, and chronic pelvic pain.
- Chronic secondary pain: pain that is a symptom of another condition, such as osteoarthritis, cancer pain, neuropathic pain, or post-surgical pain.
In both categories, once pain has been present for months, the pain experience is being actively generated by a nervous system that has learned to process signals differently. That's why treatment focused only on the peripheral tissue often falls short after the acute phase has passed.
The Neuroscience of Chronic Pain
Pain is not measured at the tissue and delivered to the brain. Pain is constructed by the brain based on many inputs: sensory signals, prior learning, expectations, emotional state, attention, context, and threat appraisal. This shift, from the old Cartesian model to the modern pain neuroscience model, is the single most important change in the field over the last three decades.
Several mechanisms are now well-established:
Central sensitization. In persistent pain, spinal cord and brain circuits become progressively more responsive to input. Innocuous signals start to register as painful (allodynia), and painful signals are amplified (hyperalgesia). This is a form of learned nervous-system hypervigilance, and it's implicated across chronic primary pain conditions.
Predictive processing and pain. The brain generates predictions about the body from moment to moment. In chronic pain, those predictions become "sticky," biased toward expecting pain, which literally shapes the pain signal that reaches consciousness. This is why context, attention, and expectation demonstrably change pain intensity in the lab and the clinic.
Default Mode Network and insular changes. Neuroimaging of chronic pain populations shows persistent alterations in the default mode network, insular cortex (which integrates interoceptive signals into a felt sense of the body), and prefrontal-limbic connectivity. These are the same networks targeted by pain-focused psychotherapies.
Fear-avoidance and deconditioning loops. Fear of pain leads to avoidance of movement, which leads to deconditioning, which increases pain and reinforces the fear. Breaking this loop is central to effective treatment.
None of this makes the pain less real. It clarifies where the intervention has to happen.
How Therapy Helps
Several evidence-based psychological approaches are effective for chronic pain. The right combination depends on the specific presentation, comorbidities, and personal goals.
Cognitive-Behavioural Therapy for Chronic Pain (CBT-CP)
The most-studied psychological treatment for chronic pain. CBT-CP addresses the thoughts, behaviours, and emotional patterns that maintain suffering and disability: catastrophic thinking, fear of movement (kinesiophobia), avoidance, and the pain-mood cycle. Meta-analyses consistently show improvements in pain intensity, function, and mood.
Acceptance and Commitment Therapy (ACT)
ACT for chronic pain shifts the goal from pain elimination to values-based living with pain. It builds psychological flexibility, the ability to have pain and still do what matters, and has robust evidence across pain conditions. ACT often works well when years of pain-elimination attempts have failed.
Pain Reprocessing Therapy (PRT)
An emerging treatment developed by Alan Gordon and studied in the 2021 Ashar et al. Boulder trial, PRT targets the brain's threat appraisal of pain signals. In the randomized trial, 66 percent of participants with chronic back pain were pain-free or nearly so at 4 weeks, versus 20 percent in placebo. PRT is best suited for chronic primary pain (nociplastic pain), where central mechanisms dominate.
Emotional Awareness and Expression Therapy (EAET)
EAET targets the connection between unprocessed emotions (particularly trauma-linked emotions) and chronic pain. A 2024 VA trial in older veterans with musculoskeletal pain found EAET outperformed CBT on pain reduction (63 versus 17 percent achieving 30 percent pain reduction post-treatment). Well-suited when trauma history and unresolved emotional experience are prominent.
Pain Neuroscience Education (PNE) and Graded Activity
Explaining pain, how it works, why it persists, why it can shift, changes the pain experience itself. Combined with graded exposure to movement and activity, PNE is a foundational component of most modern pain rehabilitation programs.
Our Approach at Toronto Mental Health Clinic
Our approach to chronic pain is grounded in current pain neuroscience. We start by mapping what's actually driving your pain: how much is nociceptive (ongoing tissue signals), how much is neuropathic (nerve damage), how much is nociplastic (central sensitization). That map guides which combination of the above approaches is most likely to help.
We coordinate with your medical team: family physician, pain clinic, physiotherapist, rehabilitation physician. Psychological treatment for chronic pain is not a substitute for medical care; it's a distinct and complementary layer that targets a real, measurable driver of your pain experience.
We also treat the mood and functional consequences of chronic pain, the depression that comes from years of loss, the anxiety that comes from unpredictable flares, the identity work involved in living well with a condition that isn't fully going away. These aren't secondary; they're part of the pain picture.
Getting Support
If you're navigating chronic pain and have felt that psychological treatment either wasn't offered or wasn't taken seriously, we would encourage you to reconsider. The evidence for these approaches is strong, the mechanisms are well understood, and the goal is real functional improvement, not talking you out of your pain.
This page provides general educational information about chronic pain and is not a substitute for individualized clinical assessment or medical advice. Chronic pain often benefits from multidisciplinary care.