Psychological and behavioural effects of interferons

Immunotherapy with interferons may induce neuropsychiatric symptoms and dis orders. Interferon-alpha -based immunotherapy is used to treat patients wit h chronic hepatitis C and metastatic renal cell carcinoma. Immunotherapy wi th interferon-alpha induces symptoms such as slowness, severe fatigue, hype rsomnia, lethargy, depressed mood, mnemonic troubles, irritability, short t emper, emotional lability, social withdrawal, lack of concentration and ful l blown major depression in a considerable number of patients treated. The exact mechanism whereby interferon-alpha induces depression has remained el usive. However, there is now some evidence that interferon-alpha -based imm unotherapy induces the cytokine network, decreases the serotonergic turnove r in the brain, and induces the catabolism of tryptophan, There is evidence that interferon-alpha immunotherapy-induced depression is related to an in creased catabolism of tryptophan into kynurenine, Curt Opin Psychiatry 13:6 73-677. (C) 2000 Lippiocott Williams & Wilkins.