Unconjugated Bilirubin as a State Marker in Patients with Schizophrenia in Acute Episode. An Egyptian Study

Background: Evidence supporting a correlation between unconjugated bilirubin and schizophrenia is considerable. Most previous studies have reported a statistically relevant link between the two variables. Aim of the Work: To assess the level of unconjugated bilirubin in patients with schizophrenia in acute episode and to analyse its correlation with the psychopathological, psychosocial and neuropsychological dimensions. Patients and Methods: A sample of 80 subjects with schizophrenia; divided into two major groups: Cases (40 patients in relapse) and Controls (40 patients in remission) were recruited. Subjects were diagnosed by DSM-IV and underwent the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I), Positive and Negative Syndrome Scale (PANSS), General Assessment of Function (GAF), and Trail Making Test (TMT) were used to assess severity of symptoms, social functioning, and cognitive functioning respectively. Subjects underwent a blood draw to measure serum bilirubin level. We analysed the relation and correlation of unconjugated bilirubin with the previous scales scores. Results: The study found that patients with schizophrenia had significantly higher levels of total bilirubin, and indirect bilirubin than healthy control subjects. Only one subject (with schizophrenia) had an abnormally elevated total bilirubin level (> 1.2 mg/dL). None of the subjects had a clinically abnormal direct (> 0.3 mg/dl) or indirect bilirubin level (> 1.2 mg/dL). A statistically significant positive correlation was found between PANSS total score, PANSS N score, and PANSS G score with total, direct, and indirect bilirubin levels. Linear regression analysis showed that none of the variables entered into the analysis (age, gender, smoking, BMI, Total PANSS, PANSS P, PANSS N, PANSS G, GAF, TMT-A, TMT-B, duration of psychotic disorder, duration of untreated psychosis, and antipsychotic medications) were predictive for total or indirect bilirubin levels. However, Total PANSS, PANSS N, and PANSS G were significantly predictive for direct bilirubin levels. Conclusion : Our study managed to find a statistically significant difference for total and unconjugated bilirubin mean serum levels between patients with schizophrenia and healthy individuals. However further longitudinal studies are needed to reveal the contradictory results in literature on the unconjugated bilirubin and Schizophrenia.