Background & Aims: Schizophrenia and Major Depressive Disorder (MDD) are severe mental disorders and disturbances of immunity system are seen in their pathogenic process. Thus, in schizophrenia both general and specific components of immune system are disturbed. In MDD immunity system also changes. Numerous studies show that when depressed patients are exposed to allergen pollens, elevation of IgE with exacerbation of allergic and depression signs and symptoms are revealed. Our study compared serum level of total IgE in schizophrenia and MMD patient to find changes of IgE levels and relations between them.

Materials & Methods: In our case control study serum levels of IgE were measured in 20 schizophrenic and 20 MMD patients that were admitted to Razi Psychiatric Hospital in Urmia. The serum level of 20 other people was measured as control group. The results were analyzed by K Square and T-Test.

Results: The mean IgE serum level of schizophrenic patients was 31.4428 IU/ml.These levels were 17.7833IU/ml and 8.3756 IU/ml for MDD and control group, respectively. The mean total serum level of IgE in schizophrenic and MDD patients were more than control group, but only the differences between schizophrenic and control group was significant (p=0.008).

Conclusion: Our study revealed that specific allergic immunoglobulin increase at least in some schizophrenic patients. Increased IgE can indicate the role of B-Cell disorder of in the etiology of (at least some) schizophrenic patients.