Are Stomach Ulcers and Mental Health Related?
Stomach ulcers are caused by stomach acid that can eat away at the lining of the stomach if it becomes damaged. While historically, stomach ulcers were thought to be caused by too much stress, everything changed with the discovery of the bacterium Helicobacter pylori in 1983 (Marshall 1988). When present in the stomach, H. pylori can cause an inflammatory response. If severe enough, the protective mucous layer of the stomach can become compromised and stomach acid can create an ulceration, commonly known as a stomach or peptic ulcer. Successful treatment and eradication of H. pylori typically resolves the ulcer.
As an infection, H. pylori is usually acquired by exposure to an infected individual’s saliva or stool. Good hygiene practices can help stop the spread, although intimate partners can spread the infection to each other back and forth.
While H. pylori has become an accepted underlying cause of stomach ulcers, since its discovery, other interesting correlations have surfaced. In some cases, research suggests that the presence of H. pylori even has correlations with poor mental health.
Mental Health and H. pylori Infection
A study of over 5000 Chinese patients looked at the correlation between depression and H. pylori infection. In the study, individuals infected with H. pylori were almost 1.5 times more likely to have higher levels of depressive symptoms than patients who were not infected (Gu 2019). A separate study also appeared to confirm the findings, showing increased mental illness and insomnia for individuals infected with H. pylori (Liu 2019).
A large population study from Korea that included over 14,000 individuals found correlations between stomach ulcers and mental health (Lee 2017). The study included three main mental health outcomes: severe levels of stress, depressive symptoms and suicidal thoughts. Patients that had all three were nine times more likely to have stomach ulcers as compared to those without. Since H. pylori is known to cause 80% of stomach ulcers, the correlations likely hold for H. pylori, although H. pylori testing was not performed for the study.
In Japan, a study involving just under 1000 individuals also showed correlations between H. pylori status, inflammation of the stomach and mental health (Takeoka 2017). Of the individuals tested, 23% were infected with H. pylori with 12.2% having stomach inflammation. For infected individuals, mental health was significantly worse. In the study, women under 50 were 2.86 times more likely to be depressed and 16.4 times more likely to have significant psychological distress if they had H. pylori and stomach inflammation.
H. Pylori Treatment and Mental Health
While H. pylori appears to play a role in worsening mental health, the effect of H. pylori treatment on mental health status is poorly studied. An animal model found that both anxiety and depression symptoms improved with H. pylori eradication (Tian 2022). Some quality of life studies have found that H. pylori treatment improves both mental and physical health (Taguchi 2017), although a separate, smaller study of just 20 patients found opposing results (Bektas 2009).
Potential Mechanisms
H. pylori is known to worsen blood sugar problems (Azami 2021). Blood sugar problems are also known to correlate with depression and bipolar disorder, among other mental health diagnoses (Fernandes 2022, Miola 2023). Infections with H. pylori can lead to increased inflammation, including inflammation of the brain (Bravo 2018, Park 2022), which can negatively influence mental health. When present, H. pylori also appears to disrupt the gut flora in ways that could contribute to negative mental health outcomes (Chen 2021).
Conclusion
H. pylori is a bacteria that can infect the stomach and cause stomach ulcers, although some people may carry the bacteria without obvious symptoms. The presence of H. pylori appears to have a negative effect on mental health, potentially through increased inflammation, worsening blood sugar levels and changes to the gastrointestinal microbiome. While more definitive research is needed, eradication of H. pylori may have mental health benefits for individuals who are infected.
