Stress can contribute to anxiety and depression when living with a condition such as Crohn’s disease. Mental health symptoms may also stem from how Crohn’s disease affects a communication pathway known as the gut-brain axis.

Crohn’s disease (CD) is one of two primary types of inflammatory bowel disease (IBD). It features persistent inflammation throughout the gastrointestinal (GI) system, though it typically affects the small intestine and the upper portion of the large intestine the most.

Severe abdominal cramping and pain, chronic diarrhea, and weight loss are all common symptoms of CD, but mental health challenges also co-occur frequently. Depression and anxiety, for example, are the most common psychological conditions seen in IBD.

This article explores the connection between the gut and the brain and how CD can affect mental health in an internal communication pathway called the gut-brain axis.

The gut microbiome, an incredibly diverse, functional community of microorganisms in the GI tract, is intricately connected to a person’s mental health.

This connection comes from a two-way communication pathway called the gut-brain axis, which consists of shared neural networks, hormonal and neurotransmitter exchanges, and immune system interactions between the GI tract and the brain.

Due to the gut-brain connection, what influences the brain and central nervous system can also influence the GI tract, and changes in the GI tract can then affect cognitive functions and mental health.

The microbiome in the gut plays an important role in the gut-brain axis. It contributes to the production of hormones and neurotransmitters necessary for regulating mood, behavior, cognition, and immune responses.

The gut microbiome also supports the health and integrity of the intestinal barrier, helping to prevent harmful substances within the GI tract from entering the bloodstream and creating body-wide (systemic) inflammation.

When there is imbalance or dysfunction in the gut microbiome, it is known as dysbiosis. Dysbiosis can affect mental health by creating imbalances in hormones and neurotransmitters and triggering systemic inflammation that may affect the brain.

According to a 2023 narrative review, different microorganism imbalances in dysbiosis have a link with mental health conditions such as anxiety, depression, schizophrenia, and bipolar disorder.

In people with IBD, the gut microbiome may be less diverse (the more diversity, the better) and have a higher population of bacteria known as adherent-invasive Escherichia coli (AIEC). AIEC produces a metabolite that promotes inflammation when it comes into contact with the intestinal lining.

Due to the gut-brain connection, conditions such as CD, which include chronic inflammation in the GI tract, can negatively affect mental health by altering the gut microbiome.

Dysbiosis from CD can alter gut microbiome substances related to mood and cognition and trigger chronic inflammation that breaks down the intestinal lining. As the lining of the intestines becomes damaged, its permeability to harmful substances increases. This is known as “leaky gut.”

Leaky gut can lead to inflammation throughout the body, including within the brain. Neuroinflammation can affect the brain’s structure and function and has a link with the development of mental health conditions such as depression.

However, the relationship between the gut microbiome and CD may also be two-way. Dysbiosis may both contribute to and result from the disease processes in CD.

According to a 2022 review, leaky gut often precedes the onset of CD by several years and may be an important influencing factor in CD’s development.

Although the exact causes of CD are not fully understood, vulnerability in the GI tract, chronic inflammation, and unusual immune activity from dysbiosis may increase the risk of developing CD in people already predisposed to the condition.

People living with IBD appear to have a higher risk of experiencing coexisting anxiety and depression compared with those not living with IBD.

A 2022 systematic review and meta-analysis found approximately one-third of people with IBD experience anxiety, and around one-quarter experience depression.

While CD’s effects on the gut microbiome can account for some of this increased risk, the long-term stress associated with chronic disease management can also negatively affect mental health.

For some people, mental health can affect the severity of Crohn’s symptoms as well as overall quality of life with IBD.

Mental health conditions such as depression and anxiety can affect the function of the GI tract by altering shared chemicals and promoting inflammation. They can also contribute to lifestyle habits that may increase the risk of IBD, such as smoking, inactivity, and difficulty eating a balanced diet.

In addition, living with a mental health condition can affect how likely someone is to keep up with CD treatment or take medications as directed. Without proper self-care in this way, symptoms could worsen.

As with the gut-brain link itself, successfully treating mental health conditions when living with Crohn’s is a two-way process. Managing CD may help improve mental health conditions, and treating mental health conditions may reduce Crohn’s symptoms and improve overall quality of life.

Typically, CD treatment involves lifestyle modifications, such as smoking cessation if applicable, and medications that control inflammation and modify immune responses in the body.

Common types of drugs a doctor prescribes include:

  • aminosalicylates
  • corticosteroids
  • immunomodulators
  • biologics

Depending on individual needs, antibiotics, nonsteroidal anti-inflammatories, and antidiarrheal medications may also be a part of therapy.

When symptoms are severe, resting the GI tract by consuming a nutrient-dense liquid diet or intravenous (IV) nutrition may be discussed with your doctor. For some people, CD management can involve surgery to remove intestinal obstructions or severely damaged tissue.

Treatment of mental health conditions that coexist with CD generally involves a combination of medications and psychotherapy interventions.

Anti-anxiety medications and antidepressants can help relieve mood-related symptoms. In addition, talk therapy can address unhelpful thought and behavior patterns and instill beneficial coping strategies for life- and CD-related stress.

Mental health management and CD management may also blend together through the use of emerging microbiome therapeutics. While still in development, these therapies target optimal balance in the gut microbiome and may simultaneously benefit both ends of the gut-brain axis.

Current microbiome therapeutics under investigation for use in CD include:

  • prebiotic and probiotic supplements
  • targeted dietary modification
  • fecal microbiota transplantation

Crohn’s disease and mental health challenges often go hand in hand. The stress of living with a chronic condition combined with gut-brain axis interactions can increase the risk of experiences such as depression or anxiety.

It is never too early to speak with a doctor about CD and mental health symptoms. Even if a person is not experiencing symptoms, talking with a doctor can provide insight into individual risk factors and proactive prevention strategies.

If symptoms are present, it is important to be honest about them. Early treatment can help improve physical and mental health outcomes and overall quality of life and well-being.