Serum samples from 307 patients with various chronic mental disorders were examined for the presence of several autoantibodies. Autoantibodies detected included antinuclear antibodies (ANA) in 122/307 (39.7%), rheumatoid factor (RF) in 23/307 (7.5%), anticardiolipin antibodies (anti-CL) in 23/304 (7.6%, IgM in 12 patients, IgG in 13 patients). Isolated cases with IgG anti-dsDNA, anti-Ro(SSA), and anti-Ro(SSA)/anti-La(SSB) were also identified. The analysis of data revealed that the aging process in patients studied contributed significantly to the incidence of ANA (p less than 0.0001) and RF (p less than 0.01). In addition, the chronic administration of chlorpromazine (CPZ) was associated with the presence of ANA (p less than 0.03) as well as with the presence of IgM and/or IgG anti-CL antibodies (p less than 0.003). Finally, the diagnosis of schizophrenia correlated with the presence of ANA (p less than 0.001). This study represents the autoantibody profile of patients with chronic mental disorders and emphasizes the multifactorial origin of autoantibody response in psychiatric patients.