The role of the epidermal growth factor in the pathogenesis of schizophrenia. Clinical and diagnostic value

Research increasingly implicates neuroimmune inflammation in schizophrenia, with the epidermal growth factor (EGF) family as a potential link. This review critically evaluates EGF family members as diagnostic, risk, and treatment response markers.The most consistent finding is decreased serum EGF in chronic schizophrenia, confirmed in postmortem brain and independent of antipsychotics. First-episode data are heterogeneous, reflecting differences in medication status, population, and illness stage.Genetic studies of EGF rs4444903 show no consistent disease risk association but demonstrate a replicable, sex-specific effect on age at onset in males. Stronger evidence implicates NRG1 type IV and NRG3 polymorphisms in disease biology.Serum EGF is not a reliable treatment response marker. In summary, EGF alone is not clinically useful. Its value lies in consistent reduction in chronic patients, sex-specific effects on age at onset, and robust links of NRG1 and NRG3 to schizophrenia.