Background: Treatment with low-dose interferon alpha (IFN-alpha) is often associated with neuropsychiatric side effects. In addition to depression and anxiety, IFN-alpha associated cognitive impairment significantly affects patient's mental health and quality of life.
Aims of the study: To measure possible effects of low-dose IFN-alpha on cognitive functioning and its relationship to the development of depression and anxiety.
Method: We prospectively followed 38 patients with a chronic hepatitis B or C by neuropsychological tests and psychiatric self-rating scales during 12 weeks of low-dose treatment with IFN-alpha.
Results: Before IFN-alpha treatment, neuropsychological tests as well as self-ratings in the Beck's Depression Inventory (BDI), the Hospital Anxiety and Depression Scale (HADS) and the Self-Report Symptom Inventory 90 Items-Revised (SCL-90-R) were within the normal range. Following 12 weeks of treatment with IFN-alpha resulted in a slight, but significant increase in depression scores. Neuropsychological assessment after 12 weeks of IFN-alpha treatment showed a significant decrease of the immediate recall in the Auditory-Verbal Learning Test (AVLT) and a significant reduction of words recited in the Controlled Oral Word Association Test (COWA). Cognitive impairment did not significantly correlate with depressive symptoms or anxiety.
Conclusion: Our results indicate that even low-dose IFN-alpha induces cognitive impairment independent from depressive symptoms, which might be related to functional disturbances in the prefrontal cortex and the hippocampus. We suggest close monitoring of cognitive function during IFN-alpha treatment of chronic hepatitis.