AUTHOR=Flegr Jaroslav , Preiss Marek , Balátová Pavla 

TITLE=Depressiveness and Neuroticism in Bartonella Seropositive and Seronegative Subjects—Preregistered Case-Controls Study

JOURNAL=Frontiers in Psychiatry

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2018.00314

DOI=10.3389/fpsyt.2018.00314

ISSN=1664-0640

ABSTRACT=<p>Several recent studies have demonstrated the association of cat-related injuries with major depression and with depressiveness in the general population. It was suggested that cat-scratch disease, the infection with the bacterium <italic>Bartonella henselae</italic>, can be responsible for the observed association. However, no direct evidence for the role of the <italic>Bartonella</italic> infection in this association has been published until now. In this preregistered case-controls study performed on 250 healthy subjects tested earlier for the presence of anti-<italic>Toxoplasma</italic> IgG antibodies, we searched for the positive association between presence of anamnestic anti-<italic>Bartonella</italic> IgG antibodies and depressiveness measured with Beck II inventory, depression subscale of neuroticism measured with N-70 questionnaire, and self-reported health problems. We found that that <italic>Bartonella</italic> seropositivity was positively correlated with Beck depression only in <italic>Toxoplasma</italic>-seronegative men and negatively correlated with health in <italic>Toxoplasma</italic>-seronegative women. <italic>Bartonella</italic> seropositivity expressed protective effects against <italic>Toxoplasma</italic> seropositivity-associated increased neuroticism in men while <italic>Toxoplasma</italic>-seropositivity expressed protective effects against <italic>Bartonella</italic> seropositivity-associated health problems in women. A comparison of the patterns of association of mental and physical health problems with <italic>Bartonella</italic> seropositivity and with reported cat-related injury suggests that different factor, possibly infection with different pathogen transmitted by cat related-injuries than the <italic>B. henselae</italic>, is responsible for the observed association of cat related-injuries with depressiveness and major depression. The existence of complex interactions between <italic>Bartonella</italic> seropositivity, <italic>Toxoplasma</italic> seropositivity, and sex also suggest that the effect of symbionts on the host's phenotype must by always studied in the context of other infections, and separately for men and women.</p>