Background <p>The aim of this study was to investigate physiological differences in electrolytes and complete blood counts in adolescent patients with depression with and without psychotic symptoms. By comparing baseline data in adolescent patients, it will provide more comprehensive information for individualised diagnosis and treatment of depression.</p> Methods <p>Clinical baseline data of adolescent patients were collected, including information on gender, age, smoking history, and alcohol consumption history. In terms of electrolytes and complete blood counts, the differences between the two groups of patients were compared, and a predictive model was constructed by stepwise logistic regression, and its diagnostic value was evaluated by ROC.</p> Results <p>Ca, WBC and NE were relevant factors for the development of psychotic symptoms in adolescents (Ca: OR = 21.95; WBC: OR = 1.16; NE: OR = 1.18). The three indicators and the constructed predictive model 1 performed poorly in the ROC curve in adolescent patients, with an AUC of 0.598.</p> Conclusion <p>Blood calcium plays an important role in adolescent depression with psychotic symptoms. And leukocytes, neutrophils in depression with psychotic symptoms as an indicator of inflammation suggestive indicators for treatment and mechanism studies.</p> Limitations <p>This study was a cross-sectional study. The study population was Chinese adolescents and did not include adolescents from other regions.</p> Clinical trial number <p>Not applicable.</p>