The comparison of the characteristics of patients with schizophrenia with and without suicide behaviors in this large observational study, which included more than 10,000 patients in 10 European countries, has identified a number of significant risk factors for suicide behaviors (attempts or completed suicide): history of suicide attempts, prolactin-related adverse events, male gender, history of hospitalization for schizophrenia, indicated both by CGI depression score. This evidence concerns the gene PRL and schizophrenia.