Objective: In this study, we aimed to examine the effects of schizophrenia and affective disorders on immunoglobulin and complement levels.

Material and Methods: The study group was consisted of totally 48 patients diagnosed with schizophrenia (n=18), major depressive disorder (n=17) and bipolar disorder (n=13) according to DSM-IV. The control group was consisted of 33 healthy persons who applied to the Department of Psychiatry, College of Medicine at Firat University for driving licence examination and were evaluated to be normal. In both group, IgG, A, M, kappa, lambda, C3 and C4 were detected and compared between groups.

Results: There were statistically significant differences with respect to IgG levels between control group and schizophrenia or depressive and bipolar disorder. With respect to C3, the levels were significantly higher in patients with depressive disorder than those with schizophrenia and controls and in patients with bipolar disorder than control group. There were no statistically significant differences among groups with respect to IgA, M and C4.

Conclusion: The elevations in IgG and C3 levels support the association between immunologic system and psychiatric disorders. However, we consider that further investigations with large sample in which the drug use and the duration of illness are taken into consideration should be rule out are required.