IL6 and psychotic disorder: In addition, IL-6 levels correlated positively with anti-lipopolysaccharide (LPS) IgA antibodies in the psychosis group, and negatively with vitamin D. At the same time, the corresponding author and his collaborators tested people with schizophrenia or schizoaffective disorder (SCZ/SAD) for Bartonella infection by droplet digital PCR (ddPCR).