Yeast infection linked to mental illness

May 4, 2016
A person with an oral Candida infection. Credit: WikiCommons, source James Heilman, M.D.

In a study prompted in part by suggestions from people with mental illness, Johns Hopkins researchers found that a history of Candida yeast infections was more common in a group of men with schizophrenia or bipolar disorder than in those without these disorders, and that women with schizophrenia or bipolar disorder who tested positive for Candida performed worse on a standard memory test than women with schizophrenia or bipolar disorder who had no evidence of past infection.

The researchers caution that their findings, described online on May 4 in npj Schizophrenia—a new publication from Nature Publishing Group—do not establish a cause-and-effect relationship between and yeast infections but may support a more detailed examination into the role of lifestyle, immune system weaknesses and gut-brain connections as contributing factors to the risk of psychiatric disorders and memory impairment.

"It's far too early to single out Candida as a cause of mental illness or vice versa," says Emily Severance, Ph.D., assistant professor of pediatrics and member of the Stanley Division of Developmental Neurovirology at the Johns Hopkins University School of Medicine. "However, most Candida infections can be treated in their early stages, and clinicians should make it a point to look out for these infections in their patients with mental illness." She adds that Candida infections can also be prevented by decreased sugar intake and other dietary modifications, avoidance of unnecessary antibiotics, and improvement of hygiene.

Candida albicans is a yeastlike fungus naturally found in small amounts in human digestive tracts, but its overgrowth in warm, moist environments causes burning, itching symptoms, thrush (rashes in the throat or mouth) in infants and those with weakened immune systems, and sexually transmittable genital yeast infections in men and women. In its more serious forms, it can enter the bloodstream. In most people, the body's own healthy bacteria and functioning immune system prevent its overgrowth.

Severance says she and her team focused on a possible association between Candida susceptibility and mental illness in the wake of new evidence suggesting that schizophrenia may be related to problems with the immune system, and because some people with weakened immune systems are more susceptible to fungal infections.

Also, she says, patients and parents of patients had shared personal stories and testimonials with the researchers about their experience with yeast infections, and these discussions prompted the investigation into possible links between mental illness and the microbiome—the body's natural collection of bacteria. The researchers, she adds, chose to focus on Candida because it is one of the most common types of yeast in the body.

For the study, colleagues from the Sheppard Pratt Health System took blood samples from a group of 808 people between the ages of 18 and 65. This group was composed of 277 controls without a history of mental disorder, 261 individuals with schizophrenia and 270 people with . The researchers used the blood samples to quantify the amount of IgG class antibodies to Candida, which indicates a past infection with the yeast. After accounting for factors like age, race, medications and socioeconomic status, which could skew the results, they looked for patterns that suggested links between mental illness and infection rates.

Significantly, the team says, it found no connection between the presence of Candida antibodies and mental illness overall in the total group. But when the investigators looked only at men, they found 26 percent of those with schizophrenia had Candida antibodies, compared to 14 percent of the control males. There wasn't any difference found in infection rate between women with schizophrenia (31.3 percent) and controls (29.4 percent). The higher infection rate percentages in women over men likely reflects an increased susceptibility for this type of infection in all women.

Men with bipolar disorder had clear increases in Candida as well, with a 26.4 percent infection rate, compared to only 14 percent in male controls. But, after accounting for additional variables related to lifestyle, the researchers found that the association between men with bipolar disorder and Candida infection could likely be attributed to homelessness. However, the link between men with schizophrenia and Candida infection persisted and could not be explained by homelessness or other environmental factors. Many people who are homeless are subjected to unpredictable changes in stress, sanitation and diet, which can lead to infections like those caused by Candida.

Severance says the data add support to the idea that environmental exposures related to lifestyle and immune system factors may be linked to schizophrenia and bipolar disorder, and that those factors may be different for each illness. Similarly, specific mental illnesses and related symptoms may be very different in men versus women.

This Johns Hopkins research group, led by Robert Yolken, M.D., director of the Stanley Division of Developmental Neurovirology, had previously shown that toxoplasmosis infection could trigger schizophrenia, and this could lead to neurocognitive problems. The organism that causes toxoplasmosis is a parasite that uses cats as its primary host, but it can also infect humans and other mammals.

To determine whether infection with Candida affected any neurological responses, all participants in the new study took a 30-minute assessment of cognitive tasks to measure immediate memory, delayed memory, attention skills, use of language and visual-spatial skills.

Each of the five skills tests are scored based on an adjusted 100-point system. Results showed that control men and women with and without prior Candida infection had no measureable differences in scores in the five neurological responses. However, the researchers noticed that women with schizophrenia and bipolar disorder who had a history of Candida infection had lower scores on the memory portions of this test compared to those women with no prior infection. For example, women with schizophrenia and the highest Candida antibody levels scored about an average of 11 points lower on the test for immediate memory than the controls, from a score of 68.5 without infection to 57.4 with infection. And the women with schizophrenia and the highest Candida antibody levels scored almost 15 points lower on the test for delayed memory, from a score of 71.4 without infection to 56.2 with infection. The effect of Candida infection in women with bipolar disorder on memory test scores was smaller than that seen in women with schizophrenia but was still measureable.

"Although we cannot demonstrate a direct link between Candida infection and physiological brain processes, our data show that some factor associated with Candida infection, and possibly the organism itself, plays a role in affecting the memory of women with schizophrenia and bipolar disorder, and this is an avenue that needs to be further explored," says Severance. "Because Candida is a natural component of the human body microbiome, yeast overgrowth or infection in the digestive tract, for example, may disrupt the gut-brain axis. This disruption in conjunction with an abnormally functioning immune system could collectively disturb those brain processes that are important for memory."

Severance says they plan to take their studies of the gut-brain connection into mouse models to test for a cause-and effect-relationship with Candida and memory deficits.

The researchers emphasized that the current study design had limitations. For example, they were unable to tell where in the body the infection was located and whether or not participants had a current or past infection of Candida. The researchers were also not able to account for every possible lifestyle variable that might contribute to these results.

The researchers in the Stanley Division of Developmental Neurovirology are investigating whether pathogens, such as bacteria or viruses, may contribute or trigger certain mental disorders.

According to the National Institute of Mental Health, about 1 percent of people in the U.S. have and about 2 percent have bipolar disorder. Although these diseases have a genetic component, there is evidence that they may also be triggered by environmental factors and stress.

Explore further: Boosting gut bacteria defense system may lead to better treatments for bloodstream infections

More information: Emily G Severance et al. Candida albicans exposures, sex specificity and cognitive deficits in schizophrenia and bipolar disorder, npj Schizophrenia (2016). DOI: 10.1038/npjschz.2016.18

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HannesAlfven
1 / 5 (1) May 04, 2016
It is striking that recent conversations about the microbiome have not yet shifted to a broader discussion of the world of fungi. Fungi are extremely vigorous organisms and also parasitic, and there is an extraordinary coincidence between home remedies for cancer and anti-fungal properties. How in the world would we ever eradicate a fungal spore from the body? It is probably impossible.
JongDan
1 / 5 (2) May 04, 2016
I wonder what this tells us about certain netizens of tumblr and their fascination with vaginal yeast bread :^)
adam_russell_9615
3 / 5 (2) May 04, 2016
Isnt that yeast infection commonly caused by not brushing your teeth after eating?
And not brushing is common in those with certain types of mental illness?
oliverlu70
1 / 5 (1) May 04, 2016
Just another meaningless story about a apparent "relationship" between a mental illness and a genuine biomedical condition...
FainAvis
1 / 5 (1) May 05, 2016
Jong: I had to hose down my computer after that thought.
barakn
3 / 5 (2) May 05, 2016
Hannes,
Home remedies for cancer don't work, so it doesn't matter whether they have anti-fungal properties or not.
Cave_Man
1 / 5 (2) May 07, 2016
Hannes,
Home remedies for cancer don't work, so it doesn't matter whether they have anti-fungal properties or not.

Pretty sure they do, time and time again. The Chemo you get in mainstream medical industry does way more harm than good.

Fucking tree in Queensland found to kill cancer in HOURS. CTM has lots. Glossy privet tree fruit and astralagus m. root will cure lymphoma in like 60% of cases. Wtf do you mean Home remedies for cancer dont work, do you think drinking benzene is a home remedy?
Cave_Man
1 / 5 (1) May 07, 2016
It is striking that recent conversations about the microbiome have not yet shifted to a broader discussion of the world of fungi. Fungi are extremely vigorous organisms and also parasitic, and there is an extraordinary coincidence between home remedies for cancer and anti-fungal properties. How in the world would we ever eradicate a fungal spore from the body? It is probably impossible.

You would probably then want to focus on good fungi in your microbiome. Nature has been around a lot longer than proctor and gamble and one of them want to sell you a lot of "treatments". Can you guess which? Our refined sugar diets have probably bred some nasty candida and other microorgansms. They can barely scratch surface of microbiome diversity because they dont have the tools to look at all the kinds of microbes, like amoeba, viruses, bacteria, yeast, other Eukaryota.
unrealone1
1 / 5 (1) May 09, 2016
So Global Warming Fear is a yeast infection?

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