Understanding The Overlooked Connection Between Chronic Pain + Mental Health

Mental Health Connection

As a functional medicine expert, I have witnessed firsthand the intricate relationship between physical and mental health - specifically when it comes to chronic pain. While conventional medicine often views chronic pain as separate from mental health, they are profoundly intertwined, with each impacting the other in significant ways. All we have to do is look at the facts.

According to the American Psychiatric Association, (1) people living with chronic pain are at heightened risk for various mental health problems. In fact, 35% to 45% (2) of people who are diagnosed with chronic pain also battle depression. It’s no coincidence than that anxiety and depression also coincide at a higher rate with other conditions like back problems, fibromyalgia, and migraines.

What all this says to me is that we are not taking into consideration the root cause of these conditions. However, I believe that once we do that we can help people reclaim their emotional and physical well-being. So what’s the missing link? Of course, it all goes back to your gut.

Understanding the Gut-Brain Axis

In my newest book Gut Feelings, I talk a lot about the gut-brain axis. This special bond between these two systems starts when you are just a baby in your mother’s womb as your brain and gut are actually formed from the same fetal tissue.

This relationship between your gut and your brain facilitates communication between all areas of your body including your gut microbiome, immune system, endocrine system, and your nervous system. Since this connection impacts so many areas of your health, when either end of your gut-brain axis is out of balance it can lead to a whole slew of problems.

When it comes to chronic pain and mental health, this bidirectional relationship works to impact these conditions from both a physiological and psychological angle. On one end, problems with your gut can often present themselves in the form of anxiety and depression and on the other end, stress, fatigue, and shame from constantly being in pain can further perpetuate inflammation and sabotage your health. 

It’s a vicious cycle. But once we understand the mechanisms of how the gut-brain axis works in these conditions we can begin to address your health head on.

Physiological mechanisms of chronic pain + mental health

So how exactly does the health of your gut lead to chronic pain, and more importantly, how can it possibly impact how you feel emotionally? It all comes down to a few factors.

1. Bacterial dysbiosis

Imbalances in your microbiome - also known as bacterial dysbiosis - often seen in conditions such as irritable bowel syndrome (IBS), can contribute to both chronic pain and mental health disorders. While functional medicine has understood this relationship for a while, researchers are just starting to confirm just how real this connection truly is.

According to a recent 2019 study, (3) researchers were able to find direct evidence for the first time of bacterial dysbiosis in people dealing with fibromyalgia. They also found that the severity of a person’s chronic pain was directly influenced by the severity of their bacterial dysbiosis, proving the importance of maintaining a healthy gut.

2. Inflammation

Intestinal permeability - aka leaky gut syndrome - is another thing that can happen due to bacterial dysbiosis. When this happens, undigested food particles and bacterial endotoxins can leak into your bloodstream where they don’t belong, triggering systemic inflammation. And while inflammation has long been considered the driving force behind chronic pain, recent studies are finding that elevated inflammation in your brain is also behind everything from brain fog (4) to depression. (5) Additionally, research has shown that inflammatory cytokines that are released during chronic pain can also affect neurotransmitter function and contribute to mood changes. 

4. Neurotransmitter function

Many of your important neurotransmitters like serotonin, norepinephrine, and dopamine involved in pain modulation and mood regulation are actually made and stored inside of your gut. When you are dealing with underlying gut dysfunctions like dysbiosis, inflammation, and leaky gut syndrome it can impact your production of these neurotransmitters and ultimately, contribute to anxiety and depression.

Psychological mechanisms of chronic pain + mental health

Now, on to the other side of the coin. Psychological factors, such as trauma, stress, and shame can significantly influence the experience of chronic pain and impact your overall health. In fact, traumatic events have been linked to the development (6) of chronic pain conditions with studies showing a prevalence (7) of chronic pain conditions among people who experienced trauma as a child. Similarly, chronic stress can exacerbate pain perception through its ability to dysregulate the immune system and perpetuate inflammation.

This cycle of shame and inflammation of your gut-brain axis is a concept I talk a lot about in my book Gut Feelings, called Shameflammation. Since shame is one of the most common underlying emotions (8) found in people with chronic stress and unresolved trauma, it shows just how important it is that we address the emotional side to physical conditions like chronic pain just as much as we address this emotion in mental health. As we’ve seen, in the end it is going to benefit our health in more ways than one.

The takeaway

The reality is, chronic pain and mental health problems often go hand-in-hand. While this might seem like an uphill battle, healing is possible once we understand both the physiological and psychological factors that contribute to these conditions. By taking a holistic view to these health problems, functional medicine is able to approach healing comprehensively with diet and lifestyle tools that will work in tandem with each other.

If you are struggling with chronic pain, depression, schedule a telehealth consultation today to learn more about how we can help you using functional medicine.

As one of the first functional medicine telehealth clinics in the world, we provide webcam health consultations for people around the globe.

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  1. Chronic Pain and Mental Health Often Interconnected. American Psychiatric Association. May 2023. https://www.psychiatry.org/news-room/apa-blogs/chronic-pain-and-mental-health-interconnected
  2. Vadivelu N, Kai AM, Kodumudi G, Babayan K, Fontes M, Burg MM. Pain and Psychology-A Reciprocal Relationship. Ochsner J. 2017 Summer;17(2):173-180. PMID: 28638291; PMCID: PMC5472077.
  3. McGill University Health Centre. "Gut bacteria associated with chronic pain for first time: People with fibromyalgia show variations in microbiome composition." ScienceDaily. ScienceDaily, 20 June 2019. <www.sciencedaily.com/releases/2019/06/190620100043.htm>.
  4. Kavanagh E. Long Covid brain fog: a neuroinflammation phenomenon? Oxf Open Immunol. 2022 Sep 27;3(1):iqac007. doi: 10.1093/oxfimm/iqac007. PMID: 36846556; PMCID: PMC9914477.
  5. Milaneschi Y, Kappelmann N, Ye Z, Lamers F, Moser S, Jones PB, Burgess S, Penninx BWJH, Khandaker GM. Association of inflammation with depression and anxiety: evidence for symptom-specificity and potential causality from UK Biobank and NESDA cohorts. Mol Psychiatry. 2021 Dec;26(12):7393-7402. doi: 10.1038/s41380-021-01188-w. Epub 2021 Jun 16. Erratum in: Mol Psychiatry. 2021 Nov 16;: PMID: 34135474; PMCID: PMC8873022.
  6. Sharp TJ, Harvey AG. Chronic pain and posttraumatic stress disorder: mutual maintenance? Clin Psychol Rev. 2001 Aug;21(6):857-77. doi: 10.1016/s0272-7358(00)00071-4. PMID: 11497210.
  7. Goldberg RT, Pachas WN, Keith D. Relationship between traumatic events in childhood and chronic pain. Disabil Rehabil. 1999 Jan;21(1):23-30. doi: 10.1080/096382899298061. PMID: 10070600.
  8. López-Castro T, Saraiya T, Zumberg-Smith K, Dambreville N. Association Between Shame and Posttraumatic Stress Disorder: A Meta-Analysis. J Trauma Stress. 2019 Aug;32(4):484-495. doi: 10.1002/jts.22411. Epub 2019 Jul 10. PMID: 31291483; PMCID: PMC7500058.

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Dr. Will Cole, DNM, IFMCP, DC is a leading functional medicine expert who consults people around the globe, starting one of the first functional medicine telehealth centers in the world. Named one of the top 50 functional and integrative doctors in the nation, Dr. Will Cole provides a functional medicine approach for thyroid issues, autoimmune conditions, hormonal imbalances, digestive disorders, and brain problems. He is also the host of the popular The Art of Being Well podcast and the New York Times bestselling author of Intuitive Fasting, Ketotarian, Gut Feelings, and The Inflammation Spectrum.

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