Toxoplasma gondii is one of the most common parasites in humans and it affects one-third of the world's population. You can become infected by Toxoplasma gondii by eating undercooked meat, drinking unpasteurized milk, eating raw fruits and vegetables or touching an infected cat or the infected cat's feces. In addition, the Toxoplasma gondii's eggs are present in cat feces, and one of the most common way people are infected with Toxoplasma gondii is through contact with an infected cat.
Infants, older people, those with diseases like HIV/AIDS or pregnant women should be especially careful due to their weakened immune systems. The Toxoplasma gondii parasite has been linked to several mental disorders, including schizophrenia.
A recent study published in the journal Brain, Behavior, and Immunity took a look at the link between Toxoplasma gondii and anxiety disorders. About 6 percent of people will have been affected by a form of anxiety disorders - like generalized anxiety disorder (GAD), post-traumatic stress disorder (PTSD) or depression - in their lifetime.
The researchers found that a past Toxoplasma gondii infection was linked to GAD, but not PTSD or depression. Those with a past history of infection were twice as likely as those without a past Toxoplasma gondii infection to have generalized anxiety disorder.
There was also a link between the severity of the infection and GAD. Those with the most severe infections were three times more likely to have developed generalized anxiety disorder.
The authors wrote: "Given the tremendous personal and societal burden of GAD in the United States (Kessler et al., 2005), identifying a modifiable risk factor for GAD would have major public health implications. Current interventions for reducing T. gondii infection, such as sanitation of consumer meat, proper meat cooking, and hygienic cat feces handling, have helped to lower prevalence in the United States; yet, 1 in 10 people remain infected with T. gondii nationally (Jones et al., 2007). Further reducing the incidence of infection and reactivation will require an effective vaccine and safer chemotherapeutics (Jongert et al., 2009). Future research is needed to elucidate underlying biological mechanisms and to prospectively confirm and investigate the observed relationship between T. gondii exposure and GAD."
From the study authors: "We gratefully acknowledge Helen Meier for coordinating the DNHS project, Caroline Cheng for statistical consultation, Fuller Torrey for manuscript review, and the many Detroit residents who chose to participate in the DNHS. This work was supported by the Stanley Medical Research Institute [AEA and RY]; and the National Institutes of Health [grant numbers R01DA022720, R01DA022720-Revision, R01DA022720-S1, and R01AG040115 to AEA]. The role of the sponsors was to fund research only. The study sponsors played no role in each of the following: the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript."
