In recent times, an increasing amount of focus has been placed on understanding the aetiology of many mental illnesses such as schizophrenia and bipolar disorder. On March 24th, a study was published by Severance et al. elucidating a link between a sexually transmitted yeast infection and schizophrenia.
Candida albicans is a fungus that commonly inhabits our digestive tracts and rarely causes harm. Symptoms such as itching, thrush and genital infection, are only seen if the fungus is allowed to grow excessively, a common occurrenc in T cell deficient AIDs patients.
The study found that 26% of 261 male schizophrenic patients were producing antibodies designed to fight this fungal infection whereas only found 14% of the 277 without schizophrenia were. Similar results were seen in men with bipolar disorder. Although the same patterns were not seen in women, there did appear to be a correlation between poor performance in memory tests and Candida antibody levels. Women with the highest levels of antibody scored almost 15 points lower on delayed memory tests that those without infection, indicating that the infection could also disrupt memory.
Although these results do suggest that a link might exist, it is too soon to say if these antibodies cause mental illnesses or are a result of them. At the moment it purely suggests a correlation. Clinicians should perhaps look out for these infections in their patients and treat them where possible to try and prevent the possibility of these illnesses.
If a causal relationship were to exist, Severance and her team believe it could be due to disruption of the gut-brain axis. In conjunction with an abnormally functioning immune system, it could collectively disturb brain processes, particularly those involved in memory. Following this study, the team at John Hopkins are looking to take studies into mouse models to test for a causal relationship between candida and memory deficits.