Subthreshold mania as predictor of depression during interferon treatment in HCV+ patients without current or lifetime psychiatric disorders.

BACKGROUND: Depression is considered the most frequent interferon (IFN)-alpha-induced psychiatric disorder. However, other neuropsychiatric side effects of IFN treatment, such as irritability, anxiety, and manic episodes, are reported as well. We analyzed the impact of lifetime manic-hypomanic symptoms and anxiety on the development of depression in hepatitis-C-virus-infected subjects treated with two different types of IFN-alpha.

METHODS: At baseline, subjects received thorough diagnostic assessment to exclude lifetime or current psychiatric symptoms. During treatment, subjects were administered interviewer-based and self-report instruments.

RESULTS: Six (12%) of 49 individuals with a negative history of psychiatric disorders developed major depression during treatment with IFN. The onset of depression was significantly associated with the presence of lifetime subthreshold manic-hypomanic symptoms. Subjects exceeding manic threshold were more likely to develop depression than those below threshold (33.3% vs. 7.5%, P=.033).

CONCLUSIONS: Our data suggest that individuals treated with IFN with no past history of psychiatric disorders are more likely to develop depression if they experienced subthreshold manic-hypomanic symptoms in their lifetime. These findings derive from an exploratory study and may have important implications for the prevention of IFN-induced depression if replicated in larger studies.