D. R. Bach et al.: Elevated Bilirubin in Acute and Transient Psychotic Disorder. Pharmacopsychiatry 2010; 43: 12–16

I read with interest the paper by Drs. Bach and colleagues on the relevance of hyperbilirubinemia in acute and transient psychotic disorders. The authors’ main aim was to replicate previous findings of 2 study groups demonstrating a possible link between hyperbilirubinemia and schizophrenia [1] [2]. The authors, however, do not cite opposite studies, in which schizophrenia was associated with low serum bilirubin levels [3] [4] [5], as well as other endogenous antioxidants [6] [7]. In this regard, it is very curious that the prevalence of hyperbilirubinemia >17 μmol/L in Drs. Bach et al.'s study ranged between 15.7–33% for F2–F9 psychiatric diagnoses (2–4 times higher compared to the general population), especially when the authors admit that the Gilbert syndrome mutation is an unlikely explanation. We have proved, in our own recent study on 137 schizophrenic patients and healthy controls, that schizophrenics display significantly lower serum bilirubin levels regardless of the UGT1A1 genotypes responsible for Gilbert syndrome [8]. In this study, each increase in serum bilirubin by 1 μmol/L was associated with a 19% decrease in the odds for schizophrenia status (P=10⁻⁶), suggesting low (and thus not high) serum bilirubin levels to be a significant risk factor for this psychiatric disease.

References

• 1 Müller N, Schiller P, Ackenheil M. Coincidence of schizophrenia and hyperbilirubinemia.  Pharmacopsychiatry. 1991;  24 225-228
• 2 Miyaoka T, Seno H, Itoga M. et al . Schizophrenia-associated idiopathic unconjugated hyperbilirubinemia (Gilbert's syndrome).  J Clin Psych. 2000;  61 868-871
• 3 Yao JK, Reddy R, van Kamen DP. Abnormal age-related changes of plasma antioxidant proteins in schizophrenia.  Psych Res. 2000;  97 137-151
• 4 Yao JK, Reddy R, McElhinny LG. et al . Reduced status of plasma total antioxidant capacity in schizophrenia.  Schizoph Res. 1998;  32 1-8
• 5 Pae CU, Paik IH, Lee C. et al . Decreased plasma antioxidants in schizophrenia.  Neuropsychobiology. 2004;  50 54-56
• 6 Reddy R, Keshavan M, Yao JK. Reduced plasma antioxidants in first-episode patients with schizophrenia.  Schizophr Res. 2003;  62 205-212
• 7 Yao JK, Reddy R, van Kamen DP. Reduced level of plasma antioxidant uric acid in schizophrenia.  Psych Res. 1998;  80 29-39
• 8 Vítek L, Novotná M, Leníček M. et al . Serum bilirubin levels and UGT1A1 promoter variations in patients with schizophrenia.  Psych Res. 2010;  178 449-450

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