Can simple biomarkers of inflammation guide the diagnosis of psychiatric disorders?

Objective: In this study, we wanted to investigate the usability of routine blood samples taken at the beginning of hospitalisation in inpatients to predict the presence of psychotic symptoms in patients.

Methods: We divided the hospitalised patients into two groups those with and without psychotic symptoms according to their ICD-10 diagnosis codes. Then, we compared the complete blood count, c-reactive protein (CRP), and fasting glucose levels, which can be used as simple markers of inflammation.

Results: In this retrospective study, which included 349 patients, we found that blood leukocytes, neutrophils, CRP, and fasting glucose levels were higher in patients with psychotic symptoms than in patients without psychotic symptoms (p = 0.015; p = 0.013; p = 0.002; and p = 0.001, respectively). According to regression analysis, patients with high glucose levels were 4.9 times more likely to have psychotic symptoms than those with low glucose levels. In addition, according to the ROC analysis results; when we used 87 mg/dl as the cut-off value for fasting glucose, it was observed that it predicted psychotic symptoms with approximately 69% sensitivity and 71% specificity.

Conclusion: Although our results still have some limitations, they are promising for the future use of simple biomarkers of inflammation for the differential diagnosis of psychiatric disorders.