TGM2 and psychotic disorder: ↑ IgG and IgA to gliadin in recent-onset psychosis. ↑ IgG and IgA to gliadin in patients with multi-episode schizophrenia but lower than in recent onset. IgG to deamidated gliadin and IgA to tissue to tTG not elevated in either group. Fewer than 1% individuals in each of the groups had levels of these antibodies predictive to celiac disease No differences in the distribution of the HLA DQ2 and HLADQ8 among groups.