According to a 2023 JAMA Network Open study, approximately 21% of adults in the United States are living with chronic pain. Yet, studies show that pain is often undertreated by healthcare providers, leading to ongoing stress in patients and long-term health complications.
The cognitive and emotional toll this puts on these patients raises an important question: how does chronic pain affect the brain?
Chronic pain, defined as pain that stays active most days or every day for more than three months, engages brain regions that do far more than process pain. The prefrontal cortex, anterior cingulate cortex, amygdala, hippocampus, and other interconnected structures also govern memory, motor skills, and emotion.
That overlap is why persistent pain surfaces as difficulty with working memory, attention, and executive function alongside the physical symptoms. In one study of chronic pain patients, two thirds qualified as clinically impaired on working memory and attention, and 85% of chronic pain patients are affected by severe depression.
With the right assessment tools, healthcare providers can track the impact of chronic pain on all facets of their patients’ health. These tools can also pinpoint comorbidities, and help providers identify the treatments that will improve the lives of chronic pain patients.
Article Highlights
Chronic pain engages brain regions that do far more than process pain, which is why it shows up in memory, attention, and mood.
- About 21% of US adults live with chronic pain, and pain is frequently undertreated by providers.
- Chronic pain is pain that stays active most days or every day for more than three months.
- The regions involved include the prefrontal cortex, amygdala, and hippocampus, which also handle memory, emotion, and decision-making.
- Two thirds of chronic pain patients in one study were clinically impaired on working memory and attention, and 85% are affected by severe depression.
What are the main types of pain?
There are two different types of pain that patients display:
Acute pain
Acute pain typically has a sudden onset, identifiable source, and can be resolved with appropriate treatment. More often than not, it’s nociceptive pain, arising from injury or trauma to non-neural body tissue. This pain is usually localized and characterized by its intensity.
A few examples of acute nociceptive pain include:
- Cuts
- Bruises
- Burns
- Pulled muscles
- Broken bones
- Labor and childbirth
- Pain during surgical recovery
Inflammatory pain is a type of nociceptive pain, and presents as hypersensitivity to the damaged tissue. This can look like tenderness, swelling, redness, or heat, and typically resolves within a few days. If the inflammation lasts between 2–6 weeks, it’s referred to as subacute inflammation.
Without the proper treatment, it is possible for some acute pain to become chronic pain over time. A thorough assessment is the key to identifying the source of pain early and making a treatment plan.
Chronic pain
Pain levels and symptoms can fluctuate over that three month window. When the pain experience limits patients from working and living their daily lives, it is defined as high-impact chronic pain (HICP).
Chronic pain can present differently from patient to patient, and often does not have an immediately obvious source. Typically, it comes with an element of central sensitization, heightening patients’ pain perception.
Neuropathic pain
One common type of chronic pain is neuropathic pain, which comes from damage to the nervous system. Peripheral neuropathy arises when nerves outside of the brain and spinal cord are damaged, whereas central neuropathy is caused by damage to the central nervous system. Both types of neuropathic pain can present as a widespread pain with no clear cause, and come on in the form of a “flare” or “attack.”
Neuropathic pain is typically diagnosed through an identified lesion or disease, and presents with physical pain signals including:
- Numbness
- Shooting, stabbing, tingling or burning sensations
- Struggling to distinguish hot from cold
- Allodynia (experiencing pain from light touch)
- Hyperalgesia (heightened pain perception)
- Intermittent or chronic mobility issues
Roughly 7% of the population lives with neuropathic pain, which arises from conditions such as:
- Nerve damage
- Spinal nerve compression
- Spinal cord or brain injury
- Stroke
- Multiple sclerosis
- Parkinson’s disease
- Fibromyalgia
- HIV/AIDS
- Phantom limb pain
Chronic inflammatory pain
Chronic inflammatory diseases are the most significant cause of death in the world, and are expected to rise in the United States over the next 30 years. They can arise from things like long-term infections, prolonged exposure to foreign materials like silica dust, autoimmune disorders, and autoinflammatory disorders.
Common signs of chronic inflammatory pain include:
- Arthralgia
- Myalgia
- Chronic fatigue
- Chronic insomnia
- Gastrointestinal distress
- Fluctuations in weight
- Frequent infections
- Depression, anxiety, and mood disorders
Some of the most common chronic inflammatory conditions include:
- Diabetes
- Cardiovascular diseases
- Arthritis and other joint diseases
- Chronic back pain
- Allergies
- Chronic Obstructive Pulmonary Disease (COPD)
Several factors increase pain patients’ likeliness of inflammatory chronic pain conditions:
- Age
- Smoking
- Diet
- Weight
- Low sex hormones
- Sleep disorders
What happens in the brain in chronic pain patients?
Along with identifying the underlying causes of chronic pain, understanding what pain does to the brain itself helps physicians identify treatment options.
Which parts of the brain are associated with pain?
Multiple brain areas are associated with chronic pain, including the:
- Prefrontal cortex
- Anterior Cingulate Cortex
- Amygdala
- Hippocampus
- Nucleus Accumbens
- Periaqueductal Gray Matter (PAG)
- Neurotransmitters
- Primary and secondary somatosensory cortex
- Insular cortex
- Thalamus
- Hypothalamus
- Cerebellum
- Limbic system
- Ventral Tegmental Area (VTA)
Along with pain processing, these interconnected brain structures impact patients’ memory, motor skills, emotions and more. For example, the amygdala’s decision-making function can be impacted by chronic pain, leading to impaired decision-making.
The negative impact on cognitive function can cause patients to struggle to assess risk, or identify strategies for managing their physical and mental health. This ongoing physical and mental distress can lead to complications such as pain medication misuse.
Cognitive, mental, and emotional symptoms of chronic pain
While functional imaging doesn’t typically happen in sessions with pain clinics, there are other ways to measure the cognitive, mental, and emotional impacts of chronic pain. Understanding these elements, as well as identifying comorbidities, is essential to creating a pain management plan.
How does pain affect cognitive function?
Over time, chronic pain can have negative effects on cognitive function, including struggles with:
- Working memory
- Attention
- Executive function
- Fatigue
One study of patients with chronic pain found that two thirds of participants qualified as clinically impaired on attention and working memory. These negative effects were consistent across all ages, education levels, and the degree of sleep interruption. Even more critically, it was found that temporary pain relief had no significant impact on their results.
Memory challenges are particularly common for patients with neuropathic pain from sources like fibromyalgia. In fact, the cognitive challenges these patients experience even has its own term: fibro fog! While classic physical pain symptoms arise in fibromyalgia patients, they often report that the cognitive impairment has the highest impact on their quality of life.
Testing cognitive function can make a significant difference in diagnosing diseases like fibromyalgia. From there, healthcare providers can make treatment plans to manage chronic pain that address both physical and cognitive symptoms.
How does chronic pain affect mental health?
Chronic pain and mental health are tightly linked: 85% of chronic pain patients experience severe depression, and these patients consistently show poorer prognoses than the 15% without mental disorders.
Six of those same brain structures also regulate mood, which is why physical and emotional symptoms travel together:
- Insular cortex
- Prefrontal cortex
- Anterior cingulate
- Thalamus
- Hippocampus
- Amygdala
Along with depression, some of the most common mental health comorbidities in chronic pain patients include:
- Affective disorders
- Anxiety
- Excessive thoughts
- Abnormal thoughts
- Insomnia and sleep disruption
As many as 90% of chronic pain patients who attend pain management centers report sleep complaints. This is a complex cycle to break, because pain makes it difficult to sleep well, and then a lack of sleep heightens patients’ sensitivity to pain and provokes spontaneous pain symptoms.
This consistent lack of rest and increase in pain can cause a greater spike in anxiety for patients with chronic pain, as well as depression and other mood disorders. Tools like the PHQ-9 Measure for Depressive Symptoms include questions about sleep, and help healthcare providers get a full picture of patients’ health experiences.
The connection between physical and emotional pain
The impact of persistent pain on patients’ quality of life can lead to a great deal of emotional changes. Pain is not just physical but also an emotional experience, causing psychological symptoms. Many chronic pain patients seek psychological care.
Emotional distress can be exacerbated by factors including:
- Unpredictable pain levels
- Loss of independence
- Impaired cognitive function
- Social isolation
- The financial strain of treatment
- Unpleasant medication side effects
- Strained patient-provider relationships
- The build-up of chronic stress
Similar to sleep deprivation, chronic stress is both a factor and result of persistent pain, which can create a challenging cycle for patients. Measuring stress can help doctors understand the degree of stress in their patient’s life, and explore stress management strategies that can help break the loop.
These strategies might look different from patients who do not have chronic pain. Patients with disabilities related to brain health have to manage systemic stigma and discrimination, which add unique stressors to patient experience that strategies like meditation or journaling cannot fully address. Along with this, healthcare providers and patients might have different perceptions of what quality of life looks like.
Connecting with individuals about their specific experiences, as well as documenting them in session notes for future consultation, is the key to meaningfully supporting their emotional and mental health needs.
Measuring chronic pain’s impact on cognition and mental health
Getting a full understanding of a patient's individual experiences with chronic pain can be simplified with the right assessment tools. At Creyos, we offer healthcare providers solutions including patient self-assessment questionnaires and customizable cognitive task assessments.
Our assessments meet or exceed HIPAA standards, and can help you measure:
- Cognitive function
- Perceived stress levels
- Levels of anxiety and depression
- Patterns associated with mood disorders
- Drug and alcohol abuse
- Autism and ADHD indications
These assessments can either be completed in clinic or remotely, which can ease the burden of travel for chronic pain patients. Plus, the self-assessment tools give patients the opportunity to document their experiences.
With a complete look at individual chronic pain patients’ cognitive and mental health, healthcare providers can build treatment plans that serve their unique needs.
Turning assessment data into chronic pain treatment plans
Along with isolating cognitive and mental health comorbidities associated with chronic pain, assessment tools can also measure the impact of treatment over time. It is true that the impact of chronic pain can be measured in the brain, but the brain also has the capacity to change and heal. With appropriate physical and emotional treatment, such as a cognitive care plan, these areas can be restored.
Even if there is currently no cure for some diseases associated with chronic pain, the right tools have the capacity to address comorbidities and elevate chronic pain patients’ quality of life.
Reviewed by Mike Battista, Director of Science & Research at Creyos
Mike Battista specializes in brain health, cognition, and neuropsychological testing. He received his PhD in personality and measurement psychology at Western University in 2010 and has been doing fun and useful stuff in the intersection between science and technology ever since.