How Are Inflammation and Depression Connected?

Medically Reviewed By Nicole Washington, DO, MPH

Research shows a strong link between inflammation and depression. Inflammation may reduce the effectiveness of some treatments. Exercise and maintaining a moderate weight can help to manage inflammation and symptoms of depression. Depression is a common cause of disability worldwide. Research shows that inflammatory processes play a role in the development of depression. However, this does not mean that depression is an inflammatory condition. The connection between inflammation and depression goes deeper than that.

This article explains what research says about the connection between inflammation and depression. It also discusses the causes of inflammation that lead to depression. Finally, it goes over the symptoms and treatment for depression.

What does research say about inflammation and depression?

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Most research shows a strong link between inflammation and depression. A 2021 study Trusted Source The Lancet Highly respected journal, Expert written journal, Peer reviewed journal Go to source confirms that certain inflammatory markers, such as C-reactive protein, are present in elevated levels in people with depression.

Some research suggests Trusted Source JAMA Peer reviewed journal Go to source that this connection may be more symptom specific. Studies have shown that higher inflammation levels are especially likely to be linked to symptoms of depression. These symptoms include fatigue, decreased appetite, and social withdrawal.

A 2019 study Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source notes that depression is common among people with chronic conditions that cause inflammation. An example is multiple sclerosis. The study also states that while antidepressants can help reduce inflammation, people with high inflammation levels may find that standard depression treatments are not as effective.

Researchers at Penn Medicine point out that people can develop depression without the presence of inflammation. This is especially so for older adults. However, the researchers note that their study does not include those who already have inflammatory conditions. Therefore, these conditions may play a role in the development of depression.

According to the research, inflammation can and does play a role in the development of depression. However, the research does not indicate that everyone who develops depression will also experience inflammation. The research does suggest that those with inflammation may benefit from the addition of anti-inflammatory medications to their depression treatment plan.

What causes inflammation that leads to depression?

Various factors may cause inflammation that can lead to depression. According to a 2013 review, there is a range of risk factors for depression that can also be associated with inflammation.

The potential causes of inflammation and depression include:

  • stress and trauma
  • a diet high in saturated fats and refined sugars
  • sedentary lifestyle or lack of regular physical activity
  • obesity
  • smoking
  • atopic conditions, such as eczema and asthma
  • periodontal conditions, such as gingivitis and periodontitis
  • irregular sleep patterns
  • vitamin D deficiency

Inflammatory conditions, such as rheumatoid arthritis and lupus, may also cause both inflammation and depression.

What are the symptoms of depression?

For a diagnosis of depression, someone must experience some or all symptoms of depression most of the day, nearly every day, for at least 2 weeks Trusted Source National Institute of Neurological Disorders and Stroke Governmental authority Go to source .

The signs and symptoms of depression include:

  • having a persistent sad or empty mood
  • feeling hopeless or pessimistic
  • feeling irritable, frustrated, or restless
  • feeling worthless, guilty, or helpless
  • losing interest or pleasure in hobbies and activities
  • experiencing a decrease in energy or fatigue
  • having difficulty concentrating, remembering, or making decisions
  • having difficulty sleeping, waking early, or oversleeping
  • experiencing a change in appetite and unexpected changes in weight
  • having aches and pains, digestive issues, or headaches with no apparent physical cause
  • experiencing thoughts of suicide or death
  • experiencing attempts of suicide

If someone you know is at immediate risk of harming themselves or others, or at risk of suicide: 

  • Even if it’s tough, ask, “Are you considering suicide?” 
  • Listen without judgment.
  • Call 911 or your local emergency number. 
  • Stay with them until emergency services arrive.
  • Try to remove any weapons, medications, or other potentially harmful items.

If you or someone you know is having suicidal thoughts, contact the National Suicide Prevention Lifeline:

  • Call 988 
  • Chat with the lifeline

This service is available 24/7. 

How is depression treated?

Typical treatment for depression includes medications, psychotherapy, or a combination of the two.

Antidepressant medications help improve the way your brain uses certain chemicals that control stress and mood. Antidepressants are a common treatment for depression. They may take 4–8 weeks Trusted Source National Institute of Neurological Disorders and Stroke Governmental authority Go to source to become fully effective.

Do not stop taking antidepressants without speaking with your doctor. Sudden discontinuation of these medications can cause the depression to return or cause symptoms of withdrawal.

Some research suggests Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source that for those with inflammation and depression, the addition of anti-inflammatory medications may make treatments more effective.

Other frequently asked questions

Nicole Washington, D.O., M.P.H., has reviewed these questions people frequently ask about inflammation and depression.

How does inflammation affect mental health?

Chronic inflammation can be a cause or a large contributing factor to the development of depression in many people. It can also contribute to the development of anxiety.

How do you reduce inflammation in depression?

Anti-inflammatory medications in addition to depression treatments may help reduce inflammation. Some also suggest regular exercise and probiotics may help to reduce inflammation as well as help manage symptoms of depression. Always speak with your doctor or mental health professional before trying any additional treatments for depression and inflammation.

What vitamin is a natural antidepressant?

Vitamin D deficiency may play a role in inflammation and depression. Taking vitamin D supplements may help to reduce some of the symptoms you may experience. Always speak with your doctor before beginning the use of any supplements.

Summary

Research has shown a strong link between inflammation and depression. Not everyone who develops depression also experiences inflammation. However, depression may be more likely to occur in those with chronic inflammation.

Some suggest that for those with inflammation, the addition of anti-inflammatory medications may make depression treatments more effective.

If you have concerns about depression, speak with your doctor or mental health professional.

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  1. Berk, M., et al. (2013). So depression is an inflammatory disease, but where does the inflammation come from? https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-11-200
  2. Depression. (2023). https://www.nimh.nih.gov/health/topics/depression
  3. Jokela, M., et al. (2016). Inflammation and specific symptoms of depression. https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2470679
  4. Lee. C.-H., et al. (2019). Role of inflammation in depression and fatigue. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6658985/
  5. Penn Medicine study finds inflammation is not always linked to depression. (2022). https://www.pennmedicine.org/news/news-releases/2022/march/penn-medicine-study-finds-inflammation-is-not-always-linked-to-depression
  6. Ye, Z., et al. (2021). Role of inflammation in depression and anxiety: Tests for disorder specificity, linearity and potential causality of association in the UK Biobank. https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(21)00272-8/fulltext

Medical Reviewer: Nicole Washington, DO, MPH
Last Review Date: 2023 Apr 14
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