Aim: To study the predictive value of the vegetative-depressive symptoms of the Zung Depression Rating Scale for the occurrence of depression during treatment with peg-interferon alpha-2b of chronic hepatitis C (CHC) patients.
Methods: The predictive value of vegetative-depressive symptoms at 4 wk of treatment for the occurrence of a subsequent diagnosis of major depressive disorder (MDD) was studied in CHC patients infected after substance use in a prospective, multi-center treatment trial in Belgium. The presence of vegetative-depressive symptoms was assessed using the Zung Scale before and 4 wk after the start of antiviral treatment.
Results: Out of 49 eligible patients, 19 (39%) developed MDD. The area under the ROC curve of the vegetative Zung subscale was 0.73, P = 0.004. The sensitivity at a cut-point of > 15/35 was 95% (95% CI: 74-100). The positive predictive value equalled 44% (95% CI: 29-60).
Conclusion: In this group of Belgian CHC patients infected after substance use, antiviral treatment caused a considerable risk of depression. Seven vegetative-depressive symptoms of the Zung scale at wk 4 of treatment predicted 95% of all emerging depressions, at a price of 56% false positive test results.