High serum bilirubin predicts depression in non-stroke subjects, but it is unknown whether it also predicts post-stroke depression (PSD). This study examined the association between the risk of PSD and bilirubin level.
Six hundred and thirty-five patients with acute ischemic stroke in Hong Kong were recruited. Serum total bilirubin, alanine transaminase and alkaline phosphatase levels were measured in all patients during their hospital stay. A psychiatrist gave the Structured Clinical Interview for DSM-IV to all patients 3 months after the index stroke, with 61 patients diagnosed with PSD: 27 with major depression, 24 with minor depression and 10 with dysthymia.
In the full sample, the 25%, 50% and 75% percentile bilirubin levels were 7.0, 10.0 and 14.0 μmol/L, respectively. Significant differences were found between the PSD and non-PSD groups in terms of bilirubin level (P = 0.006). In post-hoc comparisons, the proportion of patients with bilirubin ≥14.1 μmol/L was significantly higher in the PSD group (37.7% vs 19.7%, P = 0.001). In the final regression model, bilirubin level (≥14.1 μmol/L) remained a significant independent predictor of PSD, with an odds ratio of 2.4.
High bilirubin level is associated with PSD. Further investigations are needed to clarify the underlying pathophysiological link between bilirubin level and PSD.