Our meta‐analysis showed that schizophrenia patients under antipsychotic treatment had significantly lower peripheral IGF‐1 levels compared to healthy controls, while no significant difference in peripheral IGF‐1 levels was found between schizophrenia patients regardless of the antipsychotic treatment status and healthy controls, as well as between antipsychotic naïve or free schizophrenia patients and healthy controls, and before and after initiation of antipsychotic treatment. The gene discussed is IGF1; the disease is schizophrenia.