Major depression and risk of depressive symptomatology associated with short-term and low-dose interferon-alpha treatment.

Objective: The objective of this study is to identify early patients who are at-risk for major depression (MD) induced by interferon-alpha (IFN-alpha) and evaluate the response of depressive symptoms to antidepressants.
Methods: Thirty-six consecutive patients were treated with IFN-alpha. Psychiatric evaluations were performed prior to, and at 1 and 2 months after onset of therapy and upon completion of the study. Diagnoses were made according to DSM-IV criteria, and the severity of depressive symptoms was determined by the Hamilton Depression Rating Scale score (HDRSS).
Results: Of the 36 patients studied, 7 (19%) had MD before IFN-alpha treatment, 6 of which manifested a worsening of the depressive symptomatology during treatment. Of the remaining 29 patients, 9 (31%) developed MD during treatment. The median time required for the appearance or worsening of the depressive symptoms was 15 days (range 7-25). The median HDRSS before IFN-alpha in the 36 patients was 3 (range 1-20), whereas after 1 month of therapy, it was 10 (range 1-24; P=.000004). There was a strong positive correlation in the HDRSS before and 1 month after the initiation of treatment (r=.863). Of the 14 patients with a HDRSS of 1-2 before IFN-alpha treatment, only 1 (7%) developed MD, whereas of the 15 patients with a score >3, 8 (53%) developed MD. Antidepressants resulted in a decrease of the HDRSS to the IFN-alpha pretreatment values.
Conclusion: One third of those treated with IFN-alpha developed MD. The HDRSS before treatment reveals the high- and low-risk patients for developing MD. Psychiatric evaluation should be performed prior to IFN-alpha treatment.