Mood disorders associated with interferon treatment: theoretical and practical considerations.

OBJECTIVE: To review the theoretical and clinical aspects of mood disorders associated with interferon treatment and discuss their management. DATA SOURCES: Pertinent and selected laboratory/clinical studies, review articles, letters, abstracts, and book chapters on behavioral and mood-related adverse effects of interferons published in English-language journals in the past two decades were identified by MEDLINE (June 1980-June 2000) and manual searches. DATA SELECTION AND DATA EXTRACTION: All of the publications identified were reviewed, and the relevant data were included. Studies not using criteria for psychiatric diagnosis or instruments for psychiatnc monitoring were excluded. DATA SYNTHESIS: Clinical observations and limited research data suggest that interferon treatment may be associated with mood disorders. Mood-related symptoms induced by interferons emerge in a few days or weeks and tend to be dose dependent. Their severity may necessitate discontinuation of interferon therapy and/or the use of antidepressant or antimanic agents. The mechanisms responsible for inducing or exacerbating mood disorders in interferon-treated patients have not been elucidated. There is limited evidence implicating alterations in the serotonin system.
CONCLUSIONS: While interferon therapy may trigger or induce mood-related symptoms, preexisting or stable concurrent mood disorders in remission do not necessarily constitute a contraindication to treatment with interferons. Mood disorders associated with interferon treatment can present clinical challenges. However, they may promote our understanding of mood disorders in the context of the current biologic theories of depression and mania.