〔Abstract〕 Abstract Objective To explore the predictive value of depression severity plasma thyroid-stimulating hormone and thyroid hormones in patients with schizophrenia. Methods The subjects of this study were 203 schizophrenic patients , grouped on the basis of suicidal ideation . Clinical characteristics were assessed using multiple scales . Neutrophil to lymphocyte ratio (NLR) , platelet to lymphocyte ratio (PLR) , monocyte to lymphocyte ratio (MLR) and thyroid hormones were also detected . SPSS 23 . 0 was used for statistical analyses . Results The prevalence of suicidal ideation was 21 . 7% in patients with schizophrenia. Logistic stepwise regression analyses showed that Cal- gary depression scale (CDSS) total score (OR = 1 . 490 , 95% CI = 1 . 287 - 1 . 724 , P < 0. 001) , insomnia severity index scale (ISI) total score (OR = 1 . 096 , 95% CI = 1 . 011 - 1 . 187 , P = 0. 025) , modified overt aggression scale (MOAS) total score (OR = 1 . 111 , 95% CI = 1 . 016 - 1 . 215 , P = 0. 021) , MLR(Ln) (OR = 15 . 123 , 95% CI = 3 . 868 - 59. 125 , P < 0. 001) , and triiodothyronine ( T3) ( OR = 0. 037 , 95% CI = 0. 003 - 0. 388 , P = 0. 006) were the independent influences of suicidal ideation . Additionally , receiver operating characteristic (ROC) curve analyses revealed that the five-item combination of CDSS total score , ISI total score , MOAS total score , MLR (Ln) , and T3 (AUC = 0. 908 , 95% CI = 0. 867 - 0. 949 , P < 0. 001) had better ability to identify suicidal idea- tion . Conclusion The risk of suicidal ideation is relatively high in patients with schizophrenia , and there may be stronger associations between suicidal ideation and depression , insomnia , aggression , MLR , and T3 .