Cognitive impairment with interferon treatment in patients with chronic hepatitis C.

Interferon (IFN) has various side effects, including psychiatric symptoms. Event-related potentials are used as an electrophysiologic index of cognitive disorders. Auditory event-related potentials (P300) are often used in conditions in which cognitive ability is affected. In this study, we evaluated the association between P300, used to assess cognitive impairment, and neuropsychological side effects of IFN treatment in patients with chronic hepatitis C. Subjects were 20 patients with chronic hepatitis C; 13 patients were treated with peg IFN-α2b and ribavirin (riba group), and 7 patients were treated with peg IFN-α2a (alone group). P300 was performed on all patients before treatment and after 1 week, 4 weeks, 2 months, and 3 months of treatment. In addition, 10 patients of them completed the self-rating depression scale (SDS). P300 latency was significantly prolonged at all points of measurement during IFN treatment. No correlation between the change of SDS score and the change rate of P300 latency was shown. Six patients with neuropsychological symptom had a significantly increased change rate of P300 latency compared with patients without neuropsychological symptoms (P < 0.05). Based on P300 findings, this study suggests that patients with chronic hepatitis C treated with IFN may experience significant cognitive impairment.